Huntington's disease

• Among Western populations, one in every 10,000 people has HD
• The prevalence of Huntington’s disease is higher among Māori
• On average HD patients live for 10 to 30 years after initial appearance of symptoms

Huntington’s disease (HD) is an inherited brain disorder that causes cells in specific parts of the brain to die which results in impairment of both mental capability and physical control. It is a genetic disorder caused by an expanded gene. Everybody has the gene, but those who develop the disease have a longer version of the gene. The expansion causes the gene to not work properly and eventually results in neurodegeneration. About one in every 10,000 people has HD, but one in every 1,000 are touched by HD whether at risk, as a caregiver, family member or friend. The HD gene is dominant, which means that each child born to a parent with HD has a 50% chance of having the disease.

Signs and Symptoms:

Most people with HD develop signs and symptoms in their 30s or 40s, but the disease can also emerge earlier or later in life.  When HD develops before the age of 20 it is referred to as juvenile HD. Generally, the earlier that the disease develops, the faster it progresses.

HD symptoms can be divided into three main types:

Movement: these can include involuntary movements, difficulty with balance, walking and speech

Cognitive: these can include difficulty performing everyday tasks, problems with controlling impulses and a lack of self-awareness

Psychiatric: these can include depression, withdrawal and acting out of character

Causes and Treatment:

Medication can help to improve the movement and psychiatric symptoms of HD, but there is currently no cure. The different types of therapy that may improve quality of life for those with HD include speech, physical, occupational and psychotherapy.

It is currently thought that the neurodegeneration in HD is caused by the huntingtin protein that is produced by the defective gene. Several pharmaceutical companies are trialling drugs that reduce the production of the huntingtin protein.

Support Organisation:

Huntington's Disease Association - hdauckland.org