Huntington's disease is a rare hereditary neurological disorder which causes the abnormal death of brain cells. Huntington's is also known as HD and used to be known as Huntington's chorea. It affects approximately 1 in 10,000 people of Western European descent and 1 in 1,000,000 of African and Asian descent. HD is a progressive disorder, which means that the symptoms will worsen with time.
HD is passed from one generation to the next. If a parent has the mutated gene which causes Huntington's disease, their children will each have a 50-50 chance of inheriting the gene. HD is usually hereditary, meaning
it is inherited, but, in rare occasions, an individual may develop the disease with no family history. This is thought to be caused by a genetic mutation during the development of sperm.
Symptoms of HD usually develop later in a person's life, but it is not unheard of for them to occur earlier in life. If symptoms develop before the age of 20, it is known as juvenile Huntington's disease, or juvenile HD.
Symptoms include uncontrollable movements, known as chorea, as well as balance problems and uncontrollable facial movements. Impaired speech and problems swallowing can also occur. Depression and personality changes are other symptoms of HD, as well as dementia in late stages.
Juvenile HD's symptoms are commonly compared to Parkinson's disease. Muscle stiffness and rigidity can occur in adult onset HD, but are more common in juvenile HD patients. Other juvenile HD symptoms include a decline in school performance, changes in handwriting, as well as behavior problems and seizures.
HD's symptoms will worsen over time to the point where patients will need full-time care eventually. The progression of juvenile HD is usually faster than adult onset HD.
Diagnosing HD includes in depth medical histories of both the patient and the family of the patient. Genetic blood tests can be done. For patients who are at risk for HD but not yet showing symptoms, a presymptomatic test can be done to determine if they will develop the disease at some point.
Treatments for HD cannot slow or stop its progression, but they can help manage it and minimize complications. Some medications can help control the involuntary movements and depression associated with the disease. Speech therapy can improve speech and help with swallowing to allow for proper nutrition. Physical therapy and exercise can help keep muscles strong and combat depression.
