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What is (are) Kabuki syndrome ?
Kabuki syndrome is a disorder that affects many parts of the body. It is characterized by distinctive facial features including arched eyebrows; long eyelashes; long openings of the eyelids (long palpebral fissures) with the lower lids turned out (everted) at the outside edges; a flat, broadened tip of the nose; and large protruding earlobes. The name of this disorder comes from the resemblance of its characteristic facial appearance to stage makeup used in traditional Japanese theater called Kabuki. People with Kabuki syndrome have developmental delay and intellectual disability that range from mild to severe. Affected individuals may also have seizures, an unusually small head size (microcephaly), or weak muscle tone (hypotonia). Some have eye problems such as rapid, involuntary eye movements (nystagmus) or eyes that do not look in the same direction (strabismus). Other characteristic features of Kabuki syndrome include short stature and skeletal abnormalities such as abnormal side-to-side curvature of the spine (scoliosis), short fifth fingers, or problems with the hip and knee joints. The roof of the mouth may have an abnormal opening (cleft palate) or be high and arched, and dental problems are common in affected individuals. People with Kabuki syndrome may also have fingerprints with unusual features and fleshy pads at the tips of the fingers. These prominent finger pads are called fetal finger pads because they normally occur in human fetuses; in most people they disappear before birth. A wide variety of other health problems occur in some people with Kabuki syndrome. Among the most commonly reported are heart abnormalities, frequent ear infections (otitis media), hearing loss, and early puberty.
Kabuki syndrome
How many people are affected by Kabuki syndrome ?
Kabuki syndrome occurs in approximately 1 in 32,000 newborns.
Kabuki syndrome
What are the genetic changes related to Kabuki syndrome ?
Kabuki syndrome is caused by mutations in the KMT2D gene (also known as MLL2) or the KDM6A gene. Between 55 and 80 percent of cases of Kabuki syndrome are caused by mutations in the KMT2D gene. This gene provides instructions for making an enzyme called lysine-specific methyltransferase 2D that is found in many organs and tissues of the body. Lysine-specific methyltransferase 2D functions as a histone methyltransferase. Histone methyltransferases are enzymes that modify proteins called histones. Histones are structural proteins that attach (bind) to DNA and give chromosomes their shape. By adding a molecule called a methyl group to histones (a process called methylation), histone methyltransferases control (regulate) the activity of certain genes. Lysine-specific methyltransferase 2D appears to activate certain genes that are important for development. About 6 percent of cases of Kabuki syndrome are caused by mutations in the KDM6A gene. This gene provides instructions for making an enzyme called lysine-specific demethylase 6A. This enzyme is a histone demethylase, which means that it helps to remove methyl groups from certain histones. Like lysine-specific methyltransferase 2D, lysine-specific demethylase 6A regulates the activity of certain genes, and research suggests that the two enzymes work together to control certain developmental processes. The KMT2D and KDM6A gene mutations associated with Kabuki syndrome lead to the absence of the corresponding functional enzyme. A lack of the enzymes produced from these genes disrupts normal histone methylation and impairs proper activation of certain genes in many of the body's organs and tissues, resulting in the abnormalities of development and function characteristic of Kabuki syndrome. Some people with Kabuki syndrome have no identified KMT2D or KDM6A gene mutation. The cause of the disorder in these individuals is unknown.
Kabuki syndrome
Is Kabuki syndrome inherited ?
When Kabuki syndrome is caused by mutations in the KMT2D gene, it is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. When Kabuki syndrome is caused by mutations in the KDM6A gene, it is inherited in an X-linked dominant pattern. The KDM6A gene is located on the X chromosome, which is one of the two sex chromosomes. In females (who have two X chromosomes), a mutation in one of the two copies of the gene in each cell is sufficient to cause the disorder. In males (who have only one X chromosome), a mutation in the only copy of the gene in each cell causes the disorder. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. Most cases of Kabuki syndrome result from a new mutation in one of these genes and occur in people with no history of the disorder in their family. In a few cases, an affected person is believed to have inherited the mutation from one affected parent.
Kabuki syndrome
What are the treatments for Kabuki syndrome ?
These resources address the diagnosis or management of Kabuki syndrome: - Boston Children's Hospital - Gene Review: Gene Review: Kabuki Syndrome - Genetic Testing Registry: Kabuki make-up syndrome - Genetic Testing Registry: Kabuki syndrome 2 These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
Kabuki syndrome
What is (are) familial glucocorticoid deficiency ?
Familial glucocorticoid deficiency is a condition that occurs when the adrenal glands, which are hormone-producing glands located on top of each kidney, do not produce certain hormones called glucocorticoids. These hormones, which include cortisol and corticosterone, aid in immune system function, play a role in maintaining normal blood sugar levels, help trigger nerve cell signaling in the brain, and serve many other purposes in the body. A shortage of adrenal hormones (adrenal insufficiency) causes the signs and symptoms of familial glucocorticoid deficiency. These signs and symptoms often begin in infancy or early childhood. Most affected children first develop low blood sugar (hypoglycemia). These hypoglycemic children can fail to grow and gain weight at the expected rate (failure to thrive). If left untreated, hypoglycemia can lead to seizures, learning difficulties, and other neurological problems. Hypoglycemia that is left untreated for prolonged periods can lead to neurological damage and death. Other features of familial glucocorticoid deficiency can include recurrent infections and skin coloring darker than that of other family members (hyperpigmentation). There are multiple types of familial glucocorticoid deficiency, which are distinguished by their genetic cause.
familial glucocorticoid deficiency
How many people are affected by familial glucocorticoid deficiency ?
The prevalence of familial glucocorticoid deficiency is unknown.
familial glucocorticoid deficiency
What are the genetic changes related to familial glucocorticoid deficiency ?
Mutations in the MC2R, MRAP, and NNT genes account for the majority of cases of familial glucocorticoid deficiency; mutations in other genes, some known and some unidentified, can also cause this condition. The MC2R gene provides instructions for making a protein called adrenocorticotropic hormone (ACTH) receptor, which is found primarily in the adrenal glands. The protein produced from the MRAP gene transports the ACTH receptor from the interior of the cell to the cell membrane. When the ACTH receptor is embedded within the cell membrane, it is turned on (activated) by the MRAP protein. Activated ACTH receptor can then attach (bind) to ACTH, and this binding triggers the adrenal glands to produce glucocorticoids. MC2R gene mutations lead to the production of a receptor that cannot be transported to the cell membrane or, if it does get to the cell membrane, cannot bind to ACTH. MRAP gene mutations impair the transport of the ACTH receptor to the cell membrane. Without the binding of the ACTH receptor to its hormone, there is no signal to trigger the adrenal glands to produce glucocorticoids. The NNT gene provides instructions for making an enzyme called nicotinamide nucleotide transhydrogenase. This enzyme is found embedded in the inner membrane of structures called mitochondria, which are the energy-producing centers of cells. This enzyme helps produce a substance called NADPH, which is involved in removing potentially toxic molecules called reactive oxygen species that can damage DNA, proteins, and cell membranes. NNT gene mutations impair the enzyme's ability to produce NADPH, leading to an increase in reactive oxygen species in adrenal gland tissues. Over time, these toxic molecules can impair the function of adrenal gland cells and lead to their death (apoptosis), diminishing the production of glucocorticoids.
familial glucocorticoid deficiency
Is familial glucocorticoid deficiency inherited ?
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
familial glucocorticoid deficiency
What are the treatments for familial glucocorticoid deficiency ?
These resources address the diagnosis or management of familial glucocorticoid deficiency: - Genetic Testing Registry: ACTH resistance - Genetic Testing Registry: Glucocorticoid deficiency 2 - Genetic Testing Registry: Glucocorticoid deficiency 3 - Genetic Testing Registry: Glucocorticoid deficiency 4 - Genetic Testing Registry: Natural killer cell deficiency, familial isolated These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
familial glucocorticoid deficiency
What is (are) Walker-Warburg syndrome ?
Walker-Warburg syndrome is an inherited disorder that affects development of the muscles, brain, and eyes. It is the most severe of a group of genetic conditions known as congenital muscular dystrophies, which cause muscle weakness and wasting (atrophy) beginning very early in life. The signs and symptoms of Walker-Warburg syndrome are present at birth or in early infancy. Because of the severity of the problems caused by Walker-Warburg syndrome, most affected individuals do not survive past age 3. Walker-Warburg syndrome affects the skeletal muscles, which are muscles the body uses for movement. Affected babies have weak muscle tone (hypotonia) and are sometimes described as "floppy." The muscle weakness worsens over time. Walker-Warburg syndrome also affects the brain; individuals with this condition typically have a brain abnormality called cobblestone lissencephaly, in which the surface of the brain lacks the normal folds and grooves and instead develops a bumpy, irregular appearance (like that of cobblestones). They may also have a buildup of fluid in the brain (hydrocephalus) or abnormalities of other parts of the brain, including a region called the cerebellum and the part of the brain that connects to the spinal cord (the brainstem). These changes in the structure of the brain lead to significantly delayed development and intellectual disability. Some individuals with Walker-Warburg syndrome experience seizures. Eye abnormalities are also characteristic of Walker-Warburg syndrome. These can include unusually small eyeballs (microphthalmia), enlarged eyeballs caused by increased pressure in the eyes (buphthalmos), clouding of the lenses of the eyes (cataracts), and problems with the nerve that relays visual information from the eyes to the brain (the optic nerve). These eye problems lead to vision impairment in affected individuals.
Walker-Warburg syndrome
How many people are affected by Walker-Warburg syndrome ?
Walker-Warburg syndrome is estimated to affect 1 in 60,500 newborns worldwide.
Walker-Warburg syndrome
What are the genetic changes related to Walker-Warburg syndrome ?
Walker-Warburg syndrome can be caused by mutations in one of several genes, including POMT1, POMT2, ISPD, FKTN, FKRP, and LARGE. The proteins produced from these genes modify another protein called alpha ()-dystroglycan; this modification, called glycosylation, is required for -dystroglycan to function. The -dystroglycan protein helps anchor the structural framework inside each cell (cytoskeleton) to the lattice of proteins and other molecules outside the cell (extracellular matrix). In skeletal muscles, the anchoring function of -dystroglycan helps stabilize and protect muscle fibers. In the brain, it helps direct the movement (migration) of nerve cells (neurons) during early development. Mutations in these genes prevent glycosylation of -dystroglycan, which disrupts its normal function. Without functional -dystroglycan to stabilize muscle cells, muscle fibers become damaged as they repeatedly contract and relax with use. The damaged fibers weaken and die over time, leading to progressive weakness of the skeletal muscles. Defective -dystroglycan also affects the migration of neurons during the early development of the brain. Instead of stopping when they reach their intended destinations, some neurons migrate past the surface of the brain into the fluid-filled space that surrounds it. Researchers believe that this problem with neuronal migration causes cobblestone lissencephaly in children with Walker-Warburg syndrome. Less is known about the effects of the gene mutations in other parts of the body, including the eyes. Mutations in the POMT1, POMT2, ISPD, FKTN, FKRP, and LARGE genes are found in only about half of individuals with Walker-Warburg syndrome. Other genes, some of which have not been identified, are likely involved in the development of this condition. Because Walker-Warburg syndrome involves a malfunction of -dystroglycan, this condition is classified as a dystroglycanopathy.
Walker-Warburg syndrome
Is Walker-Warburg syndrome inherited ?
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
Walker-Warburg syndrome
What are the treatments for Walker-Warburg syndrome ?
These resources address the diagnosis or management of Walker-Warburg syndrome: - Gene Review: Gene Review: Congenital Muscular Dystrophy Overview - Genetic Testing Registry: Walker-Warburg congenital muscular dystrophy These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
Walker-Warburg syndrome
What is (are) Wolman disease ?
Wolman disease is a rare inherited condition involving the breakdown and use of fats and cholesterol in the body (lipid metabolism). In affected individuals, harmful amounts of lipids accumulate in the spleen, liver, bone marrow, small intestine, small hormone-producing glands on top of each kidney (adrenal glands), and lymph nodes. In addition to fat deposits, calcium deposits in the adrenal glands are also seen. Infants with Wolman disease are healthy and active at birth but soon develop signs and symptoms of the disorder. These may include an enlarged liver and spleen (hepatosplenomegaly), poor weight gain, low muscle tone, a yellow tint to the skin and the whites of the eyes (jaundice), vomiting, diarrhea, developmental delay, low amounts of iron in the blood (anemia), and poor absorption of nutrients from food. Children affected by this condition develop severe malnutrition and generally do not survive past early childhood.
Wolman disease
How many people are affected by Wolman disease ?
Wolman disease is estimated to occur in 1 in 350,000 newborns.
Wolman disease
What are the genetic changes related to Wolman disease ?
Mutations in the LIPA gene cause Wolman disease. The LIPA gene provides instructions for producing an enzyme called lysosomal acid lipase. This enzyme is found in the lysosomes (compartments that digest and recycle materials in the cell), where it processes lipids such as cholesteryl esters and triglycerides so they can be used by the body. Mutations in this gene lead to a shortage of lysosomal acid lipase and the accumulation of triglycerides, cholesteryl esters, and other kinds of fats within the cells and tissues of affected individuals. This accumulation as well as malnutrition caused by the body's inability to use lipids properly result in the signs and symptoms of Wolman disease.
Wolman disease
Is Wolman disease inherited ?
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
Wolman disease
What are the treatments for Wolman disease ?
These resources address the diagnosis or management of Wolman disease: - Genetic Testing Registry: Lysosomal acid lipase deficiency These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
Wolman disease
What is (are) glycogen storage disease type VI ?
Glycogen storage disease type VI (also known as GSDVI or Hers disease) is an inherited disorder caused by an inability to break down a complex sugar called glycogen in liver cells. A lack of glycogen breakdown interferes with the normal function of the liver. The signs and symptoms of GSDVI typically begin in infancy to early childhood. The first sign is usually an enlarged liver (hepatomegaly). Affected individuals may also have low blood sugar (hypoglycemia) or a buildup of lactic acid in the body (lactic acidosis) during prolonged periods without food (fasting). The signs and symptoms of GSDVI tend to improve with age; most adults with this condition do not have any related health problems.
glycogen storage disease type VI
How many people are affected by glycogen storage disease type VI ?
The exact prevalence of GSDVI is unknown. At least 11 cases have been reported in the medical literature, although this condition is likely to be underdiagnosed because it can be difficult to detect in children with mild symptoms or adults with no symptoms. GSDVI is more common in the Old Older Mennonite population, with an estimated incidence of 1 in 1,000 individuals.
glycogen storage disease type VI
What are the genetic changes related to glycogen storage disease type VI ?
Mutations in the PYGL gene cause GSDVI. The PYGL gene provides instructions for making an enzyme called liver glycogen phosphorylase. This enzyme is found only in liver cells, where it breaks down glycogen into a type of sugar called glucose-1-phosphate. Additional steps convert glucose-1-phosphate into glucose, a simple sugar that is the main energy source for most cells in the body. PYGL gene mutations prevent liver glycogen phosphorylase from breaking down glycogen effectively. As a result, liver cells cannot use glycogen for energy. Since glycogen cannot be broken down, it accumulates within liver cells, causing these cells to become enlarged and dysfunctional.
glycogen storage disease type VI
Is glycogen storage disease type VI inherited ?
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
glycogen storage disease type VI
What are the treatments for glycogen storage disease type VI ?
These resources address the diagnosis or management of glycogen storage disease type VI: - Gene Review: Gene Review: Glycogen Storage Disease Type VI - Genetic Testing Registry: Glycogen storage disease, type VI These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
glycogen storage disease type VI
What is (are) guanidinoacetate methyltransferase deficiency ?
Guanidinoacetate methyltransferase deficiency is an inherited disorder that primarily affects the brain and muscles. Without early treatment, people with this disorder have neurological problems that are usually severe. These problems include intellectual disability, speech development limited to a few words, and recurrent seizures (epilepsy). Affected individuals may also exhibit autistic behaviors that affect communication and social interaction or self-injurious behaviors such as head-banging. Other features of this disorder can include involuntary movements (extrapyramidal dysfunction) such as tremors or facial tics. People with guanidinoacetate methyltransferase deficiency may have weak muscle tone and delayed development of motor skills such as sitting or walking. In severe cases they may lose previously acquired skills such as the ability to support their head or to sit unsupported.
guanidinoacetate methyltransferase deficiency
How many people are affected by guanidinoacetate methyltransferase deficiency ?
Guanidinoacetate methyltransferase deficiency is a very rare disorder. About 80 affected individuals have been described in the medical literature. Of these, approximately one-third are of Portuguese origin.
guanidinoacetate methyltransferase deficiency
What are the genetic changes related to guanidinoacetate methyltransferase deficiency ?
Mutations in the GAMT gene cause guanidinoacetate methyltransferase deficiency. The GAMT gene provides instructions for making the enzyme guanidinoacetate methyltransferase. This enzyme participates in the two-step production (synthesis) of the compound creatine from the protein building blocks (amino acids) glycine, arginine, and methionine. Specifically, guanidinoacetate methyltransferase controls the second step of this process. In this step, creatine is produced from another compound called guanidinoacetate. Creatine is needed for the body to store and use energy properly. GAMT gene mutations impair the ability of the guanidinoacetate methyltransferase enzyme to participate in creatine synthesis, resulting in a shortage of creatine. The effects of guanidinoacetate methyltransferase deficiency are most severe in organs and tissues that require large amounts of energy, especially the brain.
guanidinoacetate methyltransferase deficiency
Is guanidinoacetate methyltransferase deficiency inherited ?
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
guanidinoacetate methyltransferase deficiency
What are the treatments for guanidinoacetate methyltransferase deficiency ?
These resources address the diagnosis or management of guanidinoacetate methyltransferase deficiency: - Gene Review: Gene Review: Creatine Deficiency Syndromes - Genetic Testing Registry: Deficiency of guanidinoacetate methyltransferase These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
guanidinoacetate methyltransferase deficiency
What is (are) enlarged parietal foramina ?
Enlarged parietal foramina is an inherited condition of impaired skull development. It is characterized by enlarged openings (foramina) in the parietal bones, which are the two bones that form the top and sides of the skull. This condition is due to incomplete bone formation (ossification) within the parietal bones. The openings are symmetrical and circular in shape, ranging in size from a few millimeters to several centimeters wide. Parietal foramina are a normal feature of fetal development, but typically they close before the baby is born, usually by the fifth month of pregnancy. However, in people with this condition, the parietal foramina remain open throughout life. The enlarged parietal foramina are soft to the touch due to the lack of bone at those areas of the skull. People with enlarged parietal foramina usually do not have any related health problems; however, scalp defects, seizures, and structural brain abnormalities have been noted in a small percentage of affected people. Pressure applied to the openings can lead to severe headaches, and individuals with this condition have an increased risk of brain damage or skull fractures if any trauma is experienced in the area of the openings. There are two forms of enlarged parietal foramina, called type 1 and type 2, which differ in their genetic cause.
enlarged parietal foramina
How many people are affected by enlarged parietal foramina ?
The prevalence of enlarged parietal foramina is estimated to be 1 in 15,000 to 50,000 individuals.
enlarged parietal foramina
What are the genetic changes related to enlarged parietal foramina ?
Mutations in the ALX4 gene account for 60 percent of cases of enlarged parietal foramina and mutations in the MSX2 gene account for 40 percent of cases. These genes provide instructions for producing proteins called transcription factors, which are required for proper development throughout the body. Transcription factors attach (bind) to specific regions of DNA and help control the activity of particular genes. The ALX4 and MSX2 transcription factor proteins are involved in regulating genes that are needed in various cell processes in early development. Mutations in either the ALX4 or MSX2 gene likely impair the ability of their respective transcription factors to bind to DNA. As a result, the regulation of multiple genes is altered, which disrupts a number of necessary cell functions. The processes that guide skull development seem to be particularly sensitive to changes in the activity of these transcription factors. If the condition is caused by a mutation in the MSX2 gene, it is called enlarged parietal foramina type 1. Mutations in the ALX4 gene cause enlarged parietal foramina type 2. There appears to be no difference in the size of the openings between enlarged parietal foramina types 1 and 2.
enlarged parietal foramina
Is enlarged parietal foramina inherited ?
This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In most cases, an affected person has one parent with the condition. However, in rare cases, people who inherit an altered gene do not have enlarged parietal foramina. (This situation is known as reduced penetrance.)
enlarged parietal foramina
What are the treatments for enlarged parietal foramina ?
These resources address the diagnosis or management of enlarged parietal foramina: - Gene Review: Gene Review: Enlarged Parietal Foramina - Genetic Testing Registry: Parietal foramina - Genetic Testing Registry: Parietal foramina 1 - Genetic Testing Registry: Parietal foramina 2 - MedlinePlus Encyclopedia: Skull of a Newborn These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
enlarged parietal foramina
What is (are) osteogenesis imperfecta ?
Osteogenesis imperfecta (OI) is a group of genetic disorders that mainly affect the bones. The term "osteogenesis imperfecta" means imperfect bone formation. People with this condition have bones that break easily, often from mild trauma or with no apparent cause. Multiple fractures are common, and in severe cases, can occur even before birth. Milder cases may involve only a few fractures over a person's lifetime. There are at least eight recognized forms of osteogenesis imperfecta, designated type I through type VIII. The types can be distinguished by their signs and symptoms, although their characteristic features overlap. Type I is the mildest form of osteogenesis imperfecta and type II is the most severe; other types of this condition have signs and symptoms that fall somewhere between these two extremes. Increasingly, genetic factors are used to define the different forms of osteogenesis imperfecta. The milder forms of osteogenesis imperfecta, including type I, are characterized by bone fractures during childhood and adolescence that often result from minor trauma. Fractures occur less frequently in adulthood. People with mild forms of the condition typically have a blue or grey tint to the part of the eye that is usually white (the sclera), and may develop hearing loss in adulthood. Affected individuals are usually of normal or near normal height. Other types of osteogenesis imperfecta are more severe, causing frequent bone fractures that may begin before birth and result from little or no trauma. Additional features of these conditions can include blue sclerae, short stature, hearing loss, respiratory problems, and a disorder of tooth development called dentinogenesis imperfecta. The most severe forms of osteogenesis imperfecta, particularly type II, can include an abnormally small, fragile rib cage and underdeveloped lungs. Infants with these abnormalities have life-threatening problems with breathing and often die shortly after birth.
osteogenesis imperfecta
How many people are affected by osteogenesis imperfecta ?
This condition affects an estimated 6 to 7 per 100,000 people worldwide. Types I and IV are the most common forms of osteogenesis imperfecta, affecting 4 to 5 per 100,000 people.
osteogenesis imperfecta
What are the genetic changes related to osteogenesis imperfecta ?
Mutations in the COL1A1, COL1A2, CRTAP, and P3H1 genes cause osteogenesis imperfecta. Mutations in the COL1A1 and COL1A2 genes are responsible for more than 90 percent of all cases of osteogenesis imperfecta. These genes provide instructions for making proteins that are used to assemble type I collagen. This type of collagen is the most abundant protein in bone, skin, and other connective tissues that provide structure and strength to the body. Most of the mutations that cause osteogenesis imperfecta type I occur in the COL1A1 gene. These genetic changes reduce the amount of type I collagen produced in the body, which causes bones to be brittle and to fracture easily. The mutations responsible for most cases of osteogenesis imperfecta types II, III, and IV occur in either the COL1A1 or COL1A2 gene. These mutations typically alter the structure of type I collagen molecules. A defect in the structure of type I collagen weakens connective tissues, particularly bone, resulting in the characteristic features of osteogenesis imperfecta. Mutations in the CRTAP and P3H1 genes are responsible for rare, often severe cases of osteogenesis imperfecta. Cases caused by CRTAP mutations are usually classified as type VII; when P3H1 mutations underlie the condition, it is classified as type VIII. The proteins produced from these genes work together to process collagen into its mature form. Mutations in either gene disrupt the normal folding, assembly, and secretion of collagen molecules. These defects weaken connective tissues, leading to severe bone abnormalities and problems with growth. In cases of osteogenesis imperfecta without identified mutations in one of the genes described above, the cause of the disorder is unknown. These cases include osteogenesis imperfecta types V and VI. Researchers are working to identify additional genes that may be responsible for these conditions.
osteogenesis imperfecta
Is osteogenesis imperfecta inherited ?
Most cases of osteogenesis imperfecta have an autosomal dominant pattern of inheritance, which means one copy of the altered gene in each cell is sufficient to cause the condition. Many people with type I or type IV osteogenesis imperfecta inherit a mutation from a parent who has the disorder. Most infants with more severe forms of osteogenesis imperfecta (such as type II and type III) have no history of the condition in their family. In these infants, the condition is caused by new (sporadic) mutations in the COL1A1 or COL1A2 gene. Less commonly, osteogenesis imperfecta has an autosomal recessive pattern of inheritance. Autosomal recessive inheritance means two copies of the gene in each cell are altered. The parents of a child with an autosomal recessive disorder typically are not affected, but each carry one copy of the altered gene. Some cases of osteogenesis imperfecta type III are autosomal recessive; these cases usually result from mutations in genes other than COL1A1 and COL1A2. When osteogenesis imperfecta is caused by mutations in the CRTAP or P3H1 gene, the condition also has an autosomal recessive pattern of inheritance.
osteogenesis imperfecta
What are the treatments for osteogenesis imperfecta ?
These resources address the diagnosis or management of osteogenesis imperfecta: - Gene Review: Gene Review: COL1A1/2-Related Osteogenesis Imperfecta - Genetic Testing Registry: Osteogenesis imperfecta - Genetic Testing Registry: Osteogenesis imperfecta type 5 - Genetic Testing Registry: Osteogenesis imperfecta type 6 - Genetic Testing Registry: Osteogenesis imperfecta type 7 - Genetic Testing Registry: Osteogenesis imperfecta type 8 - Genetic Testing Registry: Osteogenesis imperfecta type I - Genetic Testing Registry: Osteogenesis imperfecta type III - Genetic Testing Registry: Osteogenesis imperfecta with normal sclerae, dominant form - Genetic Testing Registry: Osteogenesis imperfecta, recessive perinatal lethal - MedlinePlus Encyclopedia: Osteogenesis Imperfecta These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
osteogenesis imperfecta
What is (are) dystonia 6 ?
Dystonia 6 is one of many forms of dystonia, which is a group of conditions characterized by involuntary movements, twisting (torsion) and tensing of various muscles, and unusual positioning of affected body parts. Dystonia 6 can appear at any age from childhood through adulthood; the average age of onset is 18. The signs and symptoms of dystonia 6 vary among affected individuals. The disorder usually first impacts muscles of the head and neck, causing problems with speaking (dysarthria) and eating (dysphagia). Eyelid twitching (blepharospasm) may also occur. Involvement of one or more limbs is common, and in some cases occurs before the head and neck problems. Dystonia 6 gradually gets worse, and it may eventually involve most of the body.
dystonia 6
How many people are affected by dystonia 6 ?
The prevalence of dystonia 6 is unknown. Studies indicate that it likely accounts for between 1 and 3 percent of all cases of dystonia. For reasons that are unclear, the disorder appears to be slightly more prevalent in females than in males.
dystonia 6
What are the genetic changes related to dystonia 6 ?
Dystonia 6 is caused by mutations in the THAP1 gene. This gene provides instructions for making a protein that is a transcription factor, which means that it attaches (binds) to specific regions of DNA and regulates the activity of other genes. Through this function, it is thought to help control several processes in the body, including the growth and division (proliferation) of endothelial cells, which line the inside surface of blood vessels and other circulatory system structures called lymphatic vessels. The THAP1 protein also plays a role in the self-destruction of cells that are no longer needed (apoptosis). Studies indicate that most of the THAP1 gene mutations that cause dystonia 6 affect the stability of the THAP1 protein, reducing the amount of functional THAP1 protein available for DNA binding. Other mutations may impair the protein's ability to bind with the correct regions of DNA. Problems with DNA binding likely disrupt the proper regulation of gene activity, leading to the signs and symptoms of dystonia 6. A particular THAP1 gene mutation is specific to a Mennonite population in the Midwestern United States in which dystonia 6 was first described. This mutation changes the DNA sequence in a region of the gene known as exon 2. Some researchers use the term DYT6 dystonia to refer to dystonia caused by this particular mutation, and the broader term THAP1 dystonia to refer to dystonia caused by any THAP1 gene mutation. In general, mutations affecting the region of the THAP1 protein that binds to DNA, including the mutation found in the Mennonite population, tend to result in more severe signs and symptoms than mutations affecting other regions of the protein.
dystonia 6
Is dystonia 6 inherited ?
This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell can be sufficient to cause the disorder. Some people who inherit the altered gene never develop the condition, a situation known as reduced penetrance.
dystonia 6
What are the treatments for dystonia 6 ?
These resources address the diagnosis or management of dystonia 6: - Gene Review: Gene Review: Dystonia Overview - Genetic Testing Registry: Dystonia 6, torsion These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
dystonia 6
What is (are) Ohdo syndrome, Maat-Kievit-Brunner type ?
The Maat-Kievit-Brunner type of Ohdo syndrome is a rare condition characterized by intellectual disability and distinctive facial features. It has only been reported in males. The intellectual disability associated with this condition varies from mild to severe, and the development of motor skills (such as sitting, standing, and walking) is delayed. Some affected individuals also have behavioral problems. Distinctive facial features often seen in this condition include a narrowing of the eye opening (blepharophimosis), droopy eyelids (ptosis), prominent cheeks, a broad nasal bridge, a nose with a rounded tip, a large space between the nose and upper lip (a long philtrum), and a narrow mouth. Some affected individuals also have widely set eyes (hypertelorism), an unusually small chin (micrognathia), and small and low-set ears. As people with the condition get older, these facial characteristics become more pronounced and the face becomes more triangular. Other possible signs of this condition include dental problems, weak muscle tone (hypotonia), and hearing loss.
Ohdo syndrome, Maat-Kievit-Brunner type
How many people are affected by Ohdo syndrome, Maat-Kievit-Brunner type ?
The Maat-Kievit-Brunner type of Ohdo syndrome is a very rare condition, with only a few affected individuals reported in the medical literature.
Ohdo syndrome, Maat-Kievit-Brunner type
What are the genetic changes related to Ohdo syndrome, Maat-Kievit-Brunner type ?
The Maat-Kievit-Brunner type of Ohdo syndrome results from mutations in the MED12 gene. This gene provides instructions for making a protein that helps regulate gene activity; it is thought to play an essential role in development both before and after birth. The MED12 gene mutations that cause this condition alter the structure of the MED12 protein, impairing its ability to control gene activity. It is unclear how these changes lead to the particular cognitive and physical features of the Maat-Kievit-Brunner type of Ohdo syndrome.
Ohdo syndrome, Maat-Kievit-Brunner type
Is Ohdo syndrome, Maat-Kievit-Brunner type inherited ?
This condition is inherited in an X-linked recessive pattern. The MED12 gene is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder. Because it is unlikely that females will have two altered copies of this gene, males are affected by X-linked recessive disorders much more frequently than females. Females with only one altered copy of the gene in each cell are called carriers. They do not usually experience health problems related to the condition, but they can pass the mutation to their children. Sons who inherit the altered gene will have the condition, while daughters who inherit the altered gene will be carriers. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons.
Ohdo syndrome, Maat-Kievit-Brunner type
What are the treatments for Ohdo syndrome, Maat-Kievit-Brunner type ?
These resources address the diagnosis or management of Ohdo syndrome, Maat-Kievit-Brunner type: - Genetic Testing Registry: Ohdo syndrome, X-linked These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
Ohdo syndrome, Maat-Kievit-Brunner type
What is (are) epidermal nevus ?
An epidermal nevus (plural: nevi) is an abnormal, noncancerous (benign) patch of skin caused by an overgrowth of skin cells. Epidermal nevi are typically seen at birth or develop in early childhood. They can be flat, tan patches of skin or raised, velvety patches. As the affected individual ages, the nevus can become thicker and darker and develop a wart-like (verrucous) appearance. Often, epidermal nevi follow a pattern on the skin known as the lines of Blaschko. The lines of Blaschko, which are invisible on skin, are thought to follow the paths along which cells migrate as the skin develops before birth. There are several types of epidermal nevi that are defined in part by the type of skin cell involved. The epidermis is the outermost layer of skin and is composed primarily of a specific cell type called a keratinocyte. One group of epidermal nevi, called keratinocytic or nonorganoid epidermal nevi, includes nevi that involve only keratinocytes. Other types of epidermal nevi involve additional types of epidermal cells, such as the cells that make up the hair follicles or the sebaceous glands (glands in the skin that produce a substance that protects the skin and hair). These nevi comprise a group called organoid epidermal nevi. Some affected individuals have only an epidermal nevus and no other abnormalities. However, sometimes people with an epidermal nevus also have problems in other body systems, such as the brain, eyes, or bones. In these cases, the affected individual has a condition called an epidermal nevus syndrome. There are several different epidermal nevus syndromes characterized by the type of epidermal nevus involved.
epidermal nevus
How many people are affected by epidermal nevus ?
Epidermal nevi affect approximately 1 in 1,000 people.
epidermal nevus
What are the genetic changes related to epidermal nevus ?
Mutations in the FGFR3 gene have been found in approximately 30 percent of people with a type of nevus in the keratinocytic epidermal nevi group. The gene mutations involved in most epidermal nevi are unknown. Mutations associated with an epidermal nevus are present only in the cells of the nevus, not in the normal skin cells surrounding it. Because the mutation is found in some of the body's cells but not in others, people with an epidermal nevus are said to be mosaic for the mutation. The FGFR3 gene provides instructions for the fibroblast growth factor receptor 3 (FGFR3) protein. This protein is involved in several important cellular processes, including regulation of growth and division of skin cells. The FGFR3 protein interacts with specific growth factors outside the cell to receive signals that control growth and development. When these growth factors attach to the FGFR3 protein, the protein is turned on (activated), which triggers a cascade of chemical reactions inside the cell that control growth and other cellular functions. The most common FGFR3 gene mutation in epidermal nevi creates a protein that is turned on without attachment of a growth factor, which means that the FGFR3 protein is constantly active. Cells with a mutated FGFR3 gene grow and divide more than normal cells. In addition, these mutated cells do not undergo a form of self-destruction called apoptosis as readily as normal cells. These effects result in overgrowth of skin cells, leading to epidermal nevi.
epidermal nevus
Is epidermal nevus inherited ?
This condition is generally not inherited but arises from mutations in the body's cells that occur after conception. This alteration is called a somatic mutation. Occasionally, the somatic mutation occurs in a person's reproductive cells (sperm or eggs) and is passed to the next generation. An inherited FGFR3 gene mutation is found in every cell in the body, which results in skeletal abnormalities rather than epidermal nevus.
epidermal nevus
What are the treatments for epidermal nevus ?
These resources address the diagnosis or management of epidermal nevus: - Genetic Testing Registry: Epidermal nevus These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
epidermal nevus
What is (are) infantile-onset ascending hereditary spastic paralysis ?
Infantile-onset ascending hereditary spastic paralysis is one of a group of genetic disorders known as hereditary spastic paraplegias. These disorders are characterized by progressive muscle stiffness (spasticity) and eventual paralysis of the lower limbs (paraplegia). The spasticity and paraplegia result from degeneration (atrophy) of motor neurons, which are specialized nerve cells in the brain and spinal cord that control muscle movement. Hereditary spastic paraplegias are divided into two types: pure and complicated. The pure types involve only the lower limbs, while the complicated types involve additional areas of the nervous system, affecting the upper limbs and other areas of the body. Infantile-onset ascending hereditary spastic paralysis starts as a pure hereditary spastic paraplegia, with spasticity and weakness in the legs only, but as the disorder progresses, the muscles in the arms, neck, and head become involved and features of the disorder are more characteristic of the complicated type. Affected infants are typically normal at birth, then within the first 2 years of life, the initial symptoms of infantile-onset ascending hereditary spastic paralysis appear. Early symptoms include exaggerated reflexes (hyperreflexia) and recurrent muscle spasms in the legs. As the condition progresses, affected children develop abnormal tightness and stiffness in the leg muscles and weakness in the legs and arms. Over time, muscle weakness and stiffness travels up (ascends) the body from the legs to the head and neck. Muscles in the head and neck usually weaken during adolescence; symptoms include slow eye movements and difficulty with speech and swallowing. Affected individuals may lose the ability to speak (anarthria). The leg and arm muscle weakness can become so severe as to lead to paralysis; as a result affected individuals require wheelchair assistance by late childhood or early adolescence. Intelligence is not affected in this condition. A condition called juvenile primary lateral sclerosis shares many of the features of infantile-onset ascending hereditary spastic paralysis. Both conditions have the same genetic cause and significantly impair movement beginning in childhood; however, the pattern of nerve degeneration is different. Because of their similarities, these conditions are sometimes considered the same disorder.
infantile-onset ascending hereditary spastic paralysis
How many people are affected by infantile-onset ascending hereditary spastic paralysis ?
Infantile-onset ascending hereditary spastic paralysis is a rare disorder, with at least 30 cases reported in the scientific literature.
infantile-onset ascending hereditary spastic paralysis
What are the genetic changes related to infantile-onset ascending hereditary spastic paralysis ?
Infantile-onset ascending hereditary spastic paralysis is caused by mutations in the ALS2 gene. This gene provides instructions for making the alsin protein. Alsin is produced in a wide range of tissues, with highest amounts in the brain, particularly in motor neurons. Alsin turns on (activates) multiple proteins called GTPases that convert a molecule called GTP into another molecule called GDP. GTPases play important roles in several cell processes. The GTPases that are activated by alsin are involved in the proper placement of the various proteins and fats that make up the cell membrane, the transport of molecules from the cell membrane to the interior of the cell (endocytosis), and the development of specialized structures called axons and dendrites that project from neurons and are essential for the transmission of nerve impulses. Mutations in the ALS2 gene alter the instructions for making alsin, often resulting in the production of an abnormally short alsin protein that is unstable and rapidly broken down. It is unclear exactly how ALS2 gene mutations cause infantile-onset ascending hereditary spastic paralysis. Research suggests that a lack of alsin and the subsequent loss of GTPase functions, such as endocytosis and the development of axons and dendrites, contribute to the progressive atrophy of motor neurons that is characteristic of this condition.
infantile-onset ascending hereditary spastic paralysis
Is infantile-onset ascending hereditary spastic paralysis inherited ?
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
infantile-onset ascending hereditary spastic paralysis
What are the treatments for infantile-onset ascending hereditary spastic paralysis ?
These resources address the diagnosis or management of infantile-onset ascending hereditary spastic paralysis: - Gene Review: Gene Review: ALS2-Related Disorders - Genetic Testing Registry: Infantile-onset ascending hereditary spastic paralysis These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
infantile-onset ascending hereditary spastic paralysis
What is (are) Pelizaeus-Merzbacher disease ?
Pelizaeus-Merzbacher disease is an inherited condition involving the brain and spinal cord (central nervous system). This disease is one of a group of genetic disorders called leukodystrophies. Leukodystrophies are characterized by degeneration of myelin, which is the covering that protects nerves and promotes the efficient transmission of nerve impulses. Pelizaeus-Merzbacher disease is caused by an inability to form myelin (dysmyelination). As a result, individuals with this condition have impaired intellectual functions, such as language and memory, and delayed motor skills, such as coordination and walking. Typically, motor skills are more severely affected than intellectual function; motor skills development tends to occur more slowly and usually stops in a person's teens, followed by gradual deterioration. Pelizaeus-Merzbacher disease is divided into classic and connatal types. Although these two types differ in severity, their features can overlap. Classic Pelizaeus-Merzbacher disease is the more common type. Within the first year of life, those affected with classic Pelizaeus-Merzbacher disease typically experience weak muscle tone (hypotonia), involuntary movements of the eyes (nystagmus), and delayed development of motor skills such as crawling or walking. As the child gets older, nystagmus usually stops but other movement disorders develop, including muscle stiffness (spasticity), problems with movement and balance (ataxia), and involuntary jerking (choreiform movements). Connatal Pelizaeus-Merzbacher disease is the more severe of the two types. Symptoms can begin in infancy and include problems feeding, a whistling sound when breathing, progressive spasticity leading to joint deformities (contractures) that restrict movement, speech difficulties (dysarthria), ataxia, and seizures. Those affected with connatal Pelizaeus-Merzbacher disease show little development of motor skills and intellectual function.
Pelizaeus-Merzbacher disease
How many people are affected by Pelizaeus-Merzbacher disease ?
The prevalence of Pelizaeus-Merzbacher disease is estimated to be 1 in 200,000 to 500,000 males in the United States. This condition rarely affects females.
Pelizaeus-Merzbacher disease
What are the genetic changes related to Pelizaeus-Merzbacher disease ?
Mutations in the PLP1 gene cause Pelizaeus-Merzbacher disease. The PLP1 gene provides instructions for producing proteolipid protein 1 and a modified version (isoform) of proteolipid protein 1, called DM20. Proteolipid protein 1 and DM20 are primarily located in the central nervous system and are the main proteins found in myelin, the fatty covering that insulates nerve fibers. A lack of proteolipid protein 1 and DM20 can cause dysmyelination, which can impair nervous system function, resulting in the signs and symptoms of Pelizaeus-Merzbacher disease. It is estimated that 5 percent to 20 percent of people with Pelizaeus-Merzbacher disease do not have identified mutations in the PLP1 gene. In these cases, the cause of the condition is unknown.
Pelizaeus-Merzbacher disease
Is Pelizaeus-Merzbacher disease inherited ?
This condition is inherited in an X-linked recessive pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. Because females have two copies of the X chromosome, one altered copy of the gene in each cell usually leads to less severe symptoms in females than in males, or may cause no symptoms at all. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. In X-linked recessive inheritance, a female with one altered copy of the gene in each cell is called a carrier. She can pass on the gene, but generally does not experience signs and symptoms of the disorder. Some females who carry a PLP1 mutation, however, may experience muscle stiffness and a decrease in intellectual function. Females with one PLP1 mutation have an increased risk of experiencing progressive deterioration of cognitive functions (dementia) later in life.
Pelizaeus-Merzbacher disease
What are the treatments for Pelizaeus-Merzbacher disease ?
These resources address the diagnosis or management of Pelizaeus-Merzbacher disease: - Gene Review: Gene Review: PLP1-Related Disorders - Genetic Testing Registry: Pelizaeus-Merzbacher disease These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
Pelizaeus-Merzbacher disease
What is (are) arginine:glycine amidinotransferase deficiency ?
Arginine:glycine amidinotransferase deficiency is an inherited disorder that primarily affects the brain. People with this disorder have mild to moderate intellectual disability and delayed speech development. Some affected individuals develop autistic behaviors that affect communication and social interaction. They may experience seizures, especially when they have a fever. Children with arginine:glycine amidinotransferase deficiency may not gain weight and grow at the expected rate (failure to thrive), and have delayed development of motor skills such as sitting and walking. Affected individuals may also have weak muscle tone and tend to tire easily.
arginine:glycine amidinotransferase deficiency
How many people are affected by arginine:glycine amidinotransferase deficiency ?
The prevalence of arginine:glycine amidinotransferase deficiency is unknown. The disorder has been identified in only a few families.
arginine:glycine amidinotransferase deficiency
What are the genetic changes related to arginine:glycine amidinotransferase deficiency ?
Mutations in the GATM gene cause arginine:glycine amidinotransferase deficiency. The GATM gene provides instructions for making the enzyme arginine:glycine amidinotransferase. This enzyme participates in the two-step production (synthesis) of the compound creatine from the protein building blocks (amino acids) glycine, arginine, and methionine. Specifically, arginine:glycine amidinotransferase controls the first step of the process. In this step, a compound called guanidinoacetic acid is produced by transferring a cluster of nitrogen and hydrogen atoms called a guanidino group from arginine to glycine. Guanidinoacetic acid is converted to creatine in the second step of the process. Creatine is needed for the body to store and use energy properly. GATM gene mutations impair the ability of the arginine:glycine amidinotransferase enzyme to participate in creatine synthesis, resulting in a shortage of creatine. The effects of arginine:glycine amidinotransferase deficiency are most severe in organs and tissues that require large amounts of energy, especially the brain.
arginine:glycine amidinotransferase deficiency
Is arginine:glycine amidinotransferase deficiency inherited ?
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
arginine:glycine amidinotransferase deficiency
What are the treatments for arginine:glycine amidinotransferase deficiency ?
These resources address the diagnosis or management of arginine:glycine amidinotransferase deficiency: - Gene Review: Gene Review: Creatine Deficiency Syndromes - Genetic Testing Registry: Arginine:glycine amidinotransferase deficiency These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
arginine:glycine amidinotransferase deficiency
What is (are) Pendred syndrome ?
Pendred syndrome is a disorder typically associated with hearing loss and a thyroid condition called a goiter. A goiter is an enlargement of the thyroid gland, which is a butterfly-shaped organ at the base of the neck that produces hormones. If a goiter develops in a person with Pendred syndrome, it usually forms between late childhood and early adulthood. In most cases, this enlargement does not cause the thyroid to malfunction. In most people with Pendred syndrome, severe to profound hearing loss caused by changes in the inner ear (sensorineural hearing loss) is evident at birth. Less commonly, hearing loss does not develop until later in infancy or early childhood. Some affected individuals also have problems with balance caused by dysfunction of the vestibular system, which is the part of the inner ear that helps maintain the body's balance and orientation. An inner ear abnormality called an enlarged vestibular aqueduct (EVA) is a characteristic feature of Pendred syndrome. The vestibular aqueduct is a bony canal that connects the inner ear with the inside of the skull. Some affected individuals also have an abnormally shaped cochlea, which is a snail-shaped structure in the inner ear that helps process sound. The combination of an enlarged vestibular aqueduct and an abnormally shaped cochlea is known as Mondini malformation. Pendred syndrome shares features with other hearing loss and thyroid conditions, and it is unclear whether they are best considered as separate disorders or as a spectrum of related signs and symptoms. These conditions include a form of nonsyndromic hearing loss (hearing loss that does not affect other parts of the body) called DFNB4, and, in a small number of people, a form of congenital hypothyroidism resulting from an abnormally small thyroid gland (thyroid hypoplasia). All of these conditions are caused by mutations in the same gene.
Pendred syndrome
How many people are affected by Pendred syndrome ?
The prevalence of Pendred syndrome is unknown. However, researchers estimate that it accounts for 7 to 8 percent of all hearing loss that is present from birth (congenital hearing loss).
Pendred syndrome
What are the genetic changes related to Pendred syndrome ?
Mutations in the SLC26A4 gene cause about half of all cases of Pendred syndrome. The SLC26A4 gene provides instructions for making a protein called pendrin. This protein transports negatively charged particles (ions), including chloride, iodide, and bicarbonate, into and out of cells. Although the function of pendrin is not fully understood, this protein is important for maintaining the proper levels of ions in the thyroid and the inner ear. Mutations in the SLC26A4 gene alter the structure or function of pendrin, which disrupts ion transport. An imbalance of particular ions disrupts the development and function of the thyroid gland and structures in the inner ear, which leads to the characteristic features of Pendred syndrome. In people with Pendred syndrome who do not have mutations in the SLC26A4 gene, the cause of the condition is unknown. Researchers suspect that other genetic and environmental factors may influence the condition.
Pendred syndrome
Is Pendred syndrome inherited ?
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
Pendred syndrome
What are the treatments for Pendred syndrome ?
These resources address the diagnosis or management of Pendred syndrome: - Children's Hospital of Philadelphia, Center for Childhood Communication - Gene Review: Gene Review: Pendred Syndrome/DFNB4 - Genetic Testing Registry: Pendred's syndrome - MedlinePlus Encyclopedia: Goiter - MedlinePlus Encyclopedia: Hearing Loss These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
Pendred syndrome
What is (are) Poland syndrome ?
Poland syndrome is a disorder in which affected individuals are born with missing or underdeveloped muscles on one side of the body, resulting in abnormalities that can affect the chest, shoulder, arm, and hand. The extent and severity of the abnormalities vary among affected individuals. People with Poland syndrome are typically missing part of one of the major chest muscles, called the pectoralis major. In most affected individuals, the missing part is the large section of the muscle that normally runs from the upper arm to the breastbone (sternum). The abnormal pectoralis major muscle may cause the chest to appear concave. In some cases, additional muscles on the affected side of the torso, including muscles in the chest wall, side, and shoulder, may be missing or underdeveloped. There may also be rib cage abnormalities, such as shortened ribs, and the ribs may be noticeable due to less fat under the skin (subcutaneous fat). Breast and nipple abnormalities may also occur, and underarm (axillary) hair is sometimes sparse or abnormally placed. In most cases, the abnormalities in the chest area do not cause health problems or affect movement. Many people with Poland syndrome have hand abnormalities on the affected side, commonly including an underdeveloped hand with abnormally short fingers (brachydactyly); small, underdeveloped (vestigial) fingers; and some fingers that are fused together (syndactyly). This combination of hand abnormalities is called symbrachydactyly. Some affected individuals have only one or two of these features, or have a mild hand abnormality that is hardly noticeable; more severe abnormalities can cause problems with use of the hand. The bones of the forearm (radius and ulna) are shortened in some people with Poland syndrome, but this shortening may also be difficult to detect unless measured. Mild cases of Poland syndrome without hand involvement may not be evident until puberty, when the differences (asymmetry) between the two sides of the chest become more apparent. By contrast, severely affected individuals have abnormalities of the chest, hand, or both that are apparent at birth. In rare cases, severely affected individuals have abnormalities of internal organs such as a lung or a kidney, or the heart is abnormally located in the right side of the chest (dextrocardia). Rarely, chest and hand abnormalities resembling those of Poland syndrome occur on both sides of the body, but researchers disagree as to whether this condition is a variant of Poland syndrome or a different disorder.
Poland syndrome
How many people are affected by Poland syndrome ?
Poland syndrome has been estimated to occur in 1 in 20,000 newborns. For unknown reasons, this disorder occurs more than twice as often in males than in females. Poland syndrome may be underdiagnosed because mild cases without hand involvement may never come to medical attention.
Poland syndrome
What are the genetic changes related to Poland syndrome ?
The cause of Poland syndrome is unknown. Researchers have suggested that it may result from a disruption of blood flow during development before birth. This disruption is thought to occur at about the sixth week of embryonic development and affect blood vessels that will become the subclavian and vertebral arteries on each side of the body. The arteries normally supply blood to embryonic tissues that give rise to the chest wall and hand on their respective sides. Variations in the site and extent of the disruption may explain the range of signs and symptoms that occur in Poland syndrome. Abnormality of an embryonic structure called the apical ectodermal ridge, which helps direct early limb development, may also be involved in this disorder. Rare cases of Poland syndrome are thought to be caused by a genetic change that can be passed down in families, but no related genes have been identified.
Poland syndrome
Is Poland syndrome inherited ?
Most cases of Poland syndrome are sporadic, which means they are not inherited and occur in people with no history of the disorder in their families. Rarely, this condition is passed through generations in families. In these families the condition appears to be inherited in an autosomal dominant pattern, which means one copy of an altered gene in each cell is sufficient to cause the disorder, although no associated genes have been found.
Poland syndrome
What are the treatments for Poland syndrome ?
These resources address the diagnosis or management of Poland syndrome: - Children's Medical Center of Dallas - Great Ormond Street Hospital (UK): Treatment Options for Symbrachydactyly - St. Louis Children's Hospital: Chest Wall Deformities These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
Poland syndrome
What is (are) ataxia neuropathy spectrum ?
Ataxia neuropathy spectrum is part of a group of conditions called the POLG-related disorders. The conditions in this group feature a range of similar signs and symptoms involving muscle-, nerve-, and brain-related functions. Ataxia neuropathy spectrum now includes the conditions previously called mitochondrial recessive ataxia syndrome (MIRAS) and sensory ataxia neuropathy dysarthria and ophthalmoplegia (SANDO). As the name implies, people with ataxia neuropathy spectrum typically have problems with coordination and balance (ataxia) and disturbances in nerve function (neuropathy). The neuropathy can be classified as sensory, motor, or a combination of the two (mixed). Sensory neuropathy causes numbness, tingling, or pain in the arms and legs, and motor neuropathy refers to disturbance in the nerves used for muscle movement. Most people with ataxia neuropathy spectrum also have severe brain dysfunction (encephalopathy) and seizures. Some affected individuals have weakness of the external muscles of the eye (ophthalmoplegia), which leads to drooping eyelids (ptosis). Other signs and symptoms can include involuntary muscle twitches (myoclonus), liver disease, depression, migraine headaches, or blindness.
ataxia neuropathy spectrum
How many people are affected by ataxia neuropathy spectrum ?
The prevalence of ataxia neuropathy spectrum is unknown.
ataxia neuropathy spectrum
What are the genetic changes related to ataxia neuropathy spectrum ?
Ataxia neuropathy spectrum is caused by mutations in the POLG gene or, rarely, the C10orf2 gene. The POLG gene provides instructions for making one part, the alpha subunit, of a protein called polymerase gamma (pol ). The C10orf2 gene provides instructions for making a protein called Twinkle. Pol and Twinkle function in mitochondria, which are structures within cells that use oxygen to convert the energy from food into a form cells can use. Mitochondria each contain a small amount of DNA, known as mitochondrial DNA (mtDNA), which is essential for the normal function of these structures. Pol and Twinkle are both integral to the process of DNA replication by which new copies of mtDNA are produced. Mutated pol or mutated Twinkle reduce mtDNA replication. Although the mechanisms are unknown, mutations in the POLG gene often result in fewer copies of mtDNA (mtDNA depletion), and mutations in the C10orf2 gene often result in deletions of large regions of mtDNA (mtDNA deletion). MtDNA depletion or deletion occurs most commonly in muscle, brain, or liver cells. MtDNA depletion causes a decrease in cellular energy, which could account for the signs and symptoms of ataxia neuropathy spectrum. It is unclear what role mtDNA deletions play in the signs and symptoms of the condition.
ataxia neuropathy spectrum
Is ataxia neuropathy spectrum inherited ?
Ataxia neuropathy spectrum can have different inheritance patterns depending on the associated gene. Mutations in the POLG gene cause a form of the condition that is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. Mutations in the C10orf2 gene cause a form of the condition that is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder.
ataxia neuropathy spectrum
What are the treatments for ataxia neuropathy spectrum ?
These resources address the diagnosis or management of ataxia neuropathy spectrum: - Gene Review: Gene Review: POLG-Related Disorders - Genetic Testing Registry: Sensory ataxic neuropathy, dysarthria, and ophthalmoparesis - National Ataxia Foundation: Gene Testing for Hereditary Ataxia - United Mitochondrial Disease Foundation: Diagnosis of Mitochondrial Disease These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
ataxia neuropathy spectrum
What is (are) Mabry syndrome ?
Mabry syndrome is a condition characterized by intellectual disability, distinctive facial features, increased levels of an enzyme called alkaline phosphatase in the blood (hyperphosphatasia), and other signs and symptoms. People with Mabry syndrome have intellectual disability that is often moderate to severe. They typically have little to no speech development and are delayed in the development of motor skills (such as sitting, crawling, and walking). Many affected individuals have low muscle tone (hypotonia) and develop recurrent seizures (epilepsy) in early childhood. Seizures are usually the generalized tonic-clonic type, which involve muscle rigidity, convulsions, and loss of consciousness. Individuals with Mabry syndrome have distinctive facial features that include wide-set eyes (hypertelorism), long openings of the eyelids (long palpebral fissures), a nose with a broad bridge and a rounded tip, downturned corners of the mouth, and a thin upper lip. These facial features usually become less pronounced over time. Hyperphosphatasia begins within the first year of life in people with Mabry syndrome. There are many different types of alkaline phosphatase found in tissues; the type that is increased in Mabry syndrome is called the tissue non-specific type and is found throughout the body. In affected individuals, alkaline phosphatase levels in the blood are usually increased by one to two times the normal amount, but can be up to 20 times higher than normal. The elevated enzyme levels remain relatively stable over a person's lifetime. Hyperphosphatasia appears to cause no negative health effects, but this finding can help health professionals diagnose Mabry syndrome. Another common feature of Mabry syndrome is shortened bones at the ends of fingers (brachytelephalangy), which can be seen on x-ray imaging. Underdeveloped fingernails (nail hypoplasia) may also occur. Sometimes, individuals with Mabry syndrome have abnormalities of the digestive system, including narrowing or blockage of the anus (anal stenosis or anal atresia) or Hirschsprung disease, a disorder that causes severe constipation or blockage of the intestine. Rarely, affected individuals experience hearing loss. The signs and symptoms of Mabry syndrome vary among affected individuals. Those who are least severely affected have only intellectual disability and hyperphosphatasia, without distinctive facial features or the other health problems listed above.
Mabry syndrome
How many people are affected by Mabry syndrome ?
Mabry syndrome is likely a rare condition, but its prevalence is unknown. More than 20 cases have been described in the scientific literature.
Mabry syndrome
What are the genetic changes related to Mabry syndrome ?
Mutations in the PIGV, PIGO, or PGAP2 gene cause Mabry syndrome. These genes are all involved in the production (synthesis) of a molecule called a glycosylphosphosphatidylinositol (GPI) anchor. This molecule is synthesized in a series of steps. It then attaches (binds) to various proteins and binds them to the outer surface of the cell membrane, ensuring that they are available when needed. Alkaline phosphatase is an example of a protein that is bound to the cell membrane by a GPI anchor. The proteins produced from the PIGV and PIGO genes are involved in piecing together the GPI anchor. After the complete GPI anchor is attached to a protein, the protein produced from the PGAP2 gene adjusts the anchor to enhance the anchor's ability to bind to the cell membrane. Mutations in the PIGV, PIGO, or PGAP2 gene result in the production of an incomplete GPI anchor that cannot attach to proteins or to cell membranes. Proteins lacking a functional GPI anchor cannot bind to the cell membrane and are instead released from the cell. The release of non-GPI anchored alkaline phosphatase elevates the amount of this protein in the blood, causing hyperphosphatasia in people with Mabry syndrome. It is unclear how gene mutations lead to the other features of Mabry syndrome, but these signs and symptoms are likely due to a lack of proper GPI anchoring of proteins. PIGV gene mutations are the most frequent cause of Mabry syndrome, accounting for approximately half of all cases. Mutations in the PIGO and PGAP2 genes are responsible for a small proportion of Mabry syndrome. The remaining affected individuals do not have an identified mutation in any of these three genes; the cause of the condition in these individuals is unknown.
Mabry syndrome
Is Mabry syndrome inherited ?
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
Mabry syndrome
What are the treatments for Mabry syndrome ?
These resources address the diagnosis or management of Mabry syndrome: - Genetic Testing Registry: Hyperphosphatasia with mental retardation syndrome - Genetic Testing Registry: Hyperphosphatasia with mental retardation syndrome 1 - Genetic Testing Registry: Hyperphosphatasia with mental retardation syndrome 2 - Genetic Testing Registry: Hyperphosphatasia with mental retardation syndrome 3 - MedlinePlus Encyclopedia: ALP Isoenzyme Test - MedlinePlus Encyclopedia: ALP--Blood Test - Seattle Children's Hospital: Hirschsprung's Disease--Treatments These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
Mabry syndrome
What is (are) anhidrotic ectodermal dysplasia with immune deficiency ?
Anhidrotic ectodermal dysplasia with immune deficiency (EDA-ID) is a form of ectodermal dysplasia, which is a group of conditions characterized by abnormal development of ectodermal tissues including the skin, hair, teeth, and sweat glands. In addition, immune system function is reduced in people with EDA-ID. The signs and symptoms of EDA-ID are evident soon after birth. Skin abnormalities in people with EDA-ID include areas that are dry, wrinkled, or darker in color than the surrounding skin. Affected individuals tend to have sparse scalp and body hair (hypotrichosis). EDA-ID is also characterized by missing teeth (hypodontia) or teeth that are small and pointed. Most people with EDA-ID have a reduced ability to sweat (hypohidrosis) because they have fewer sweat glands than normal or their sweat glands do not function properly. An inability to sweat (anhidrosis) can lead to a dangerously high body temperature (hyperthermia), particularly in hot weather. The immune deficiency in EDA-ID varies among people with this condition. People with EDA-ID often produce abnormally low levels of proteins called antibodies or immunoglobulins. Antibodies help protect the body against infection by attaching to specific foreign particles and germs, marking them for destruction. A reduction in antibodies makes it difficult for people with this disorder to fight off infections. In EDA-ID, immune system cells called T cells and B cells have a decreased ability to recognize and respond to foreign invaders (such as bacteria, viruses, and yeast) that have sugar molecules attached to their surface (glycan antigens). Other key aspects of the immune system may also be impaired, leading to recurrent infections. People with EDA-ID commonly get infections in the lungs (pneumonia), ears (otitis media), sinuses (sinusitis), lymph nodes (lymphadenitis), skin, bones, and GI tract. Approximately one quarter of individuals with EDA-ID have disorders involving abnormal inflammation, such as inflammatory bowel disease or rheumatoid arthritis. The life expectancy of affected individuals depends of the severity of the immune deficiency; most people with this condition do not live past childhood. There are two forms of this condition that have similar signs and symptoms and are distinguished by the modes of inheritance: X-linked recessive or autosomal dominant.
anhidrotic ectodermal dysplasia with immune deficiency
How many people are affected by anhidrotic ectodermal dysplasia with immune deficiency ?
The prevalence of the X-linked recessive type of EDA-ID is estimated to be 1 in 250,000 individuals. Only a few cases of the autosomal dominant form have been described in the scientific literature.
anhidrotic ectodermal dysplasia with immune deficiency
What are the genetic changes related to anhidrotic ectodermal dysplasia with immune deficiency ?
Mutations in the IKBKG gene cause X-linked recessive EDA-ID, and mutations in the NFKBIA gene cause autosomal dominant EDA-ID. The proteins produced from these two genes regulate nuclear factor-kappa-B. Nuclear factor-kappa-B is a group of related proteins (a protein complex) that binds to DNA and controls the activity of other genes, including genes that direct the body's immune responses and inflammatory reactions. It also protects cells from certain signals that would otherwise cause them to self-destruct (undergo apoptosis). The IKBKG and NFKBIA gene mutations responsible for EDA-ID result in the production of proteins with impaired function, which reduces activation of nuclear factor-kappa-B. These changes disrupt certain signaling pathways within immune cells, resulting in immune deficiency. It is unclear how gene mutations alter the development of the skin, teeth, sweat glands, and other tissues, although it is likely caused by abnormal nuclear factor-kappa-B signaling in other types of cells.
anhidrotic ectodermal dysplasia with immune deficiency
Is anhidrotic ectodermal dysplasia with immune deficiency inherited ?
When EDA-ID is caused by mutations in the IKBKG gene, it is inherited in an X-linked recessive pattern. The IKBKG gene is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder. Because it is unlikely that females will have two altered copies of the IKBKG gene, males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. When EDA-ID is caused by mutations in the NFKBIA gene, the condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. Most cases result from new mutations in the gene and occur in people with no history of the disorder in their family.
anhidrotic ectodermal dysplasia with immune deficiency
What are the treatments for anhidrotic ectodermal dysplasia with immune deficiency ?
These resources address the diagnosis or management of anhidrotic ectodermal dysplasia with immune deficiency: - Genetic Testing Registry: Anhidrotic ectodermal dysplasia with immune deficiency - Genetic Testing Registry: Hypohidrotic ectodermal dysplasia with immune deficiency - MedlinePlus Encyclopedia: Immunodeficiency Disorders These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
anhidrotic ectodermal dysplasia with immune deficiency
What is (are) hypophosphatasia ?
Hypophosphatasia is an inherited disorder that affects the development of bones and teeth. This condition disrupts a process called mineralization, in which minerals such as calcium and phosphorus are deposited in developing bones and teeth. Mineralization is critical for the formation of bones that are strong and rigid and teeth that can withstand chewing and grinding. The signs and symptoms of hypophosphatasia vary widely and can appear anywhere from before birth to adulthood. The most severe forms of the disorder tend to occur before birth and in early infancy. Hypophosphatasia weakens and softens the bones, causing skeletal abnormalities similar to another childhood bone disorder called rickets. Affected infants are born with short limbs, an abnormally shaped chest, and soft skull bones. Additional complications in infancy include poor feeding and a failure to gain weight, respiratory problems, and high levels of calcium in the blood (hypercalcemia), which can lead to recurrent vomiting and kidney problems. These complications are life-threatening in some cases. The forms of hypophosphatasia that appear in childhood or adulthood are typically less severe than those that appear in infancy. Early loss of primary (baby) teeth is one of the first signs of the condition in children. Affected children may have short stature with bowed legs or knock knees, enlarged wrist and ankle joints, and an abnormal skull shape. Adult forms of hypophosphatasia are characterized by a softening of the bones known as osteomalacia. In adults, recurrent fractures in the foot and thigh bones can lead to chronic pain. Affected adults may lose their secondary (adult) teeth prematurely and are at increased risk for joint pain and inflammation. The mildest form of this condition, called odontohypophosphatasia, only affects the teeth. People with this disorder typically experience abnormal tooth development and premature tooth loss, but do not have the skeletal abnormalities seen in other forms of hypophosphatasia.
hypophosphatasia
How many people are affected by hypophosphatasia ?
Severe forms of hypophosphatasia affect an estimated 1 in 100,000 newborns. Milder cases, such as those that appear in childhood or adulthood, probably occur more frequently. Hypophosphatasia has been reported worldwide in people of various ethnic backgrounds. This condition appears to be most common in white populations. It is particularly frequent in a Mennonite population in Manitoba, Canada, where about 1 in 2,500 infants is born with severe features of the condition.
hypophosphatasia
What are the genetic changes related to hypophosphatasia ?
Mutations in the ALPL gene cause hypophosphatasia. The ALPL gene provides instructions for making an enzyme called alkaline phosphatase. This enzyme plays an essential role in mineralization of the skeleton and teeth. Mutations in the ALPL gene lead to the production of an abnormal version of alkaline phosphatase that cannot participate effectively in the mineralization process. A shortage of alkaline phosphatase allows several other substances, which are normally processed by the enzyme, to build up abnormally in the body. Researchers believe that a buildup of one of these compounds, inorganic pyrophosphate (PPi), underlies the defective mineralization of bones and teeth in people with hypophosphatasia. ALPL mutations that almost completely eliminate the activity of alkaline phosphatase usually result in the more severe forms of hypophosphatasia. Other mutations, which reduce but do not eliminate the activity of the enzyme, are often responsible for milder forms of the condition.
hypophosphatasia
Is hypophosphatasia inherited ?
The severe forms of hypophosphatasia that appear early in life are inherited in an autosomal recessive pattern. Autosomal recessive inheritance means that two copies of the gene in each cell are altered. Most often, the parents of an individual with an autosomal recessive disorder each carry one copy of the altered gene but do not show signs and symptoms of the disorder. Milder forms of hypophosphatasia can have either an autosomal recessive or an autosomal dominant pattern of inheritance. Autosomal dominant inheritance means that one copy of the altered gene in each cell is sufficient to cause the disorder.
hypophosphatasia
What are the treatments for hypophosphatasia ?
These resources address the diagnosis or management of hypophosphatasia: - Gene Review: Gene Review: Hypophosphatasia - Genetic Testing Registry: Adult hypophosphatasia - Genetic Testing Registry: Childhood hypophosphatasia - Genetic Testing Registry: Hypophosphatasia - Genetic Testing Registry: Infantile hypophosphatasia - MedlinePlus Encyclopedia: Osteomalacia These resources from MedlinePlus offer information about the diagnosis and management of various health conditions: - Diagnostic Tests - Drug Therapy - Surgery and Rehabilitation - Genetic Counseling - Palliative Care
hypophosphatasia