Huntington's disease

Huntington's disease (HD) is an inherited disease of the brain that affects the nervous system. The most common symptom is jerky movements of the arms and legs, known as 'chorea'. Chorea usually starts as mild twitching and gradually increases over the years. A person with HD may also have difficulties with speech, swallowing and concentration. There is no cure.

HD is caused by a defective gene. This gene is passed on from parent to child, but the condition isn't obvious at birth. The symptoms usually, but not always, first appear when the person is approaching middle age. HD is a slow, progressive condition that affects people differently. A person with HD may live for 15 to 25 years after developing the first symptoms.