Title: Genetics Basics Lesson 3: Modes of Inheritance
Headings: 
3.1  Modes of Inheritance
3.2  Autosomal Dominant Inheritance
3.3  Autosomal Recessive Inheritance
3.3.1  Autosomal Recessive Diseases
3.4  X-Linked Dominant Inheritance
3.4.1  Oral-Facial-Digital syndrome type I
3.5  X-Linked Recessive Inheritance
3.5.1  Hypohidrotic or anhidrotic ectodermal dysplasia
3.6  Complex Inheritance
3.6.1  Cleft Lip +/- Cleft Palate

Content: Genetics Basics Lesson 3: Modes of Inheritance
Genetics Basics - Lesson 3: Modes of Inheritance
3.1  Modes of Inheritance
Inheritance patterns describe how a disease is transmitted in families. These patterns help to predict the recurrence risk for relatives. In general, inheritance patterns for single gene disorders are classified based on whether they are autosomal or X-linked and whether they have a dominant or recessive pattern of inheritance. These disorders are called Mendelian disorders, after the geneticist Gregor Mendel. 3.2  Autosomal Dominant Inheritance
In autosomal dominant inheritance, only one copy of a disease allele is necessary for an individual to be susceptible to expressing the phenotype. With each pregnancy, there is a one in two (50%) chance the offspring will inherit the disease allele. Unless a new mutation has occurred, all affected individuals will have at least one parent who carries the disease allele. Autosomal dominant inheritance is often called vertical inheritance because of the transmission from parent to offspring.