Huntington's disease (HD), also known as Huntington's chorea, is a rare hereditary neurodegenerative disorder characterized by progressive motor dysfunction, cognitive decline, and psychiatric symptoms (the term 'chorea' refers to the jerky, unpredictable movements of the muscles in the face, arms and legs that is a prevalent symptom of Huntington's disease). The estimates are that the global prevalence of HD is ~2.7 per 100,000 persons. HD is caused by a mutation in the HTT gene, located on chromosome 4, which encodes the huntingtin protein. This mutation involves an expansion of a trinucleotide repeat sequence, known as CAG, within the gene. Individuals with HD inherit an expanded CAG repeat from one of their parents, leading to the production of a mutant huntingtin protein. The length of the CAG repeat is inversely correlated with the age of onset and severity of symptoms, with longer repeats generally associated with earlier onset and more severe disease. HD follows an autosomal dominant pattern of inheritance, meaning that a person who inherits a single copy of the mutant gene from one parent will develop the disease, regardless of whether the other parent carries the mutation. Each child of an affected individual has a 50% chance of inheriting the mutated gene. The mutant huntingtin protein disrupts normal cellular functions and leads to neuronal dysfunction and death, particularly in the basal ganglia and cerebral cortex of the brain. These regions are involved in movement control, cognition, and emotion regulation. Progressive degeneration of these brain areas results in the characteristic symptoms of HD, which typically worsen over time. The most prominent early symptoms of HD are often motor-related and may include involuntary movements called chorea, which are rapid, jerky, and random. Other motor symptoms can include dystonia (sustained muscle contractions causing twisting or repetitive movements), rigidity, bradykinesia (slowness of movement), and impaired coordination and balance. HD also affects cognitive function, leading to impairments in memory, executive function, attention, and decision-making. As the disease progresses, individuals may experience difficulties with language, planning, problem-solving, and other cognitive tasks. Psychiatric symptoms are common in HD and can precede motor symptoms by several years. These can include depression, anxiety, irritability, apathy, impulsivity, and obsessive-compulsive behaviors. Psychiatric symptoms can significantly impact quality of life for individuals with HD and their caregivers. While most cases of HD typically manifest in adulthood, a small percentage of individuals develop symptoms during childhood or adolescence, known as juvenile-onset HD. Juvenile-onset HD tends to progress more rapidly and may have distinct clinical features compared to adult-onset HD. Currently, there is no cure for HD, and available treatments focus on managing symptoms and improving quality of life. Medications can help alleviate motor symptoms, psychiatric symptoms, and complications such as chorea and depression. Doctors utilize an arsenal of medications to help alleviate the symptoms of Huntington's disease including antipsychotics and antidepressants. Tetrabenazine (Xenazine) and deutetrabenazine (Austedo) are two US FDA drugs approved in 2008 and 2017, respectively, for treating chorea in Huntington's disease. Physical therapy, speech therapy, and occupational therapy may also be beneficial in managing motor and functional impairments. Genetic testing can confirm the diagnosis of HD in individuals with symptoms or a family history of the disease. Genetic counseling is recommended for individuals considering testing to discuss the implications of the test results and the potential impact on themselves and their families. Ongoing research efforts aim to better understand the underlying mechanisms of HD and develop disease-modifying treatments. Clinical trials are underway to test potential therapies targeting the mutant huntingtin protein, neuroinflammation, and other pathways implicated in HD pathogenesis. Despite the challenges posed by HD, advances in research and clinical care offer hope for improved treatments and ultimately a cure for this devastating neurodegenerative disorder.