Huntington’s Disease (HD) is a genetic neurological condition which affects the central nervous system. It usually develops when individuals are in their thirties to fifties. When symptoms appear in individuals under the age of 20, the condition is known as Juvenile Onset HD, and this happens in about 10% of affected individuals.
HD is caused by a faulty gene on chromosome 4, which produces a protein called Huntingtin. Each child with a parent with HD has a 50-50 chance of inheriting the condition and a test can be performed to determine whether the faulty gene is present.
The presence of Huntingtin protein increases the rate of cell death in the brain, which, in turn, affects the sufferer’s physical and psychological functioning. Rates of deterioration vary amongst individuals.
Physical symptoms include chorea or random, jerky movements, as well as impaired gross motor control and rigidity. People may experience problems with swallowing, speaking and nutritional intake as a consequence. Psychological problems can be even more debilitating and can include anxiety, depression, mood swings and aggression, impulsiveness including inappropriate sexual behaviour, difficulties with attention and in rarer cases psychosis.
As the disease progresses often the person will require increasing levels of care.