- Named after the American physician who initially described the inherited nature of the condition in 1872.
- Not the first to describe HD which can be traced back to the Middle Ages.
- Also known as Huntington’s chorea. Chorea is derived from the Greek word for dance and describes uncontrolled body movement.
- HD is an inherited disease of the brain that affects the nervous system.
- It is caused by a defective gene that is passed from parent to child.
- The HD gene interferes with the manufacture of a particular protein known as huntingtin which appears to be crucial for proper brain development.
- The classic signs of HD include emotional, cognitive and motor disturbances.
- Huntington’s is characterised by jerky involuntary movements (chorea), but sometimes causes rigidity without abnormal movements, changes in using the limbs (apraxia), loss of control of bodily functions and dementia, including a progressive deterioration of memory, speed of thought, judgement, lack of awareness of problems and planning.
- HD is an autosomal dominant disease which means a child only needs to inherit the gene from one parent to develop HD.
- The child of an affected parent has a fifty per cent chance (like the flip of a coin) of inheriting the gene and developing the manifestations of HD.
- If the child does not inherit the gene he or she will not develop HD or transmit the gene to future generations.
- Gene testing has resulted in identifying an increasing number of individuals with HD but no family history.
- HD is found in every country in the world.
- Men and women are at equal risk of inheriting the disease.
- HD can appear at any age though manifestations typically become evident during the fourth or fifth decades of life.
- It is likely that the earlier the onset the faster the disease seems to progress.
- There is evidence that some of those who inherit the disease gene from their father are more likely to experience younger onset than those who inherit the gene from their mother.
Diagnostic Genetic testing for Huntington’s can be done to confirm the diagnosis when the disease is suspected after an examination and only after consent has been given for the test.
Predictive Genetic testing is done when a person at risk of inheriting the disease because of a family history but who has not developed the changes of the disease (preclinical) wants to know if he/ she has inherited the gene. The predictive test is taken only when there has been pre test counselling through a Clinical Genetics Service in collaboration with a neurologist.
There is no cure for Huntington’s Disease.
There are a number of medications to help control emotional and movement problems but there is no treatment to stop or reverse the course of the disease.
It is best to consult a neurologist about the management of the varied manifestations of HD.
Treatment of HD requires an integrated, multidisciplinary approach.
Throughout the illness the patient may require the skills of a number of different professionals including a GP, neurologist, psychiatrist, dietician, social worker, palliative care specialist… to name a few.
HD is a progressive disease which means the disease worsens over time.
The duration of the illness ranges from 10 to 30 years.
Symptoms are not usually presented by the patient. The patient often has poor insight into the changes occurring which vary from patient to patient.
Some patients reach the point where speech is slurred and vital functions such as swallowing, speaking and walking continue to decline. Some patients can no longer recognise family members. Many however most remain aware and can express feelings.
Scientists now believe that identifying the location of the HD gene is the first step on the road to a cure. Clinical trials of some substances which delayed the illness in mice with the HD gene are underway.
Further Information and Support
Australian Huntington's Disease Association - NSW
PO Box 178, West Ryde NSW 2114
Tel (02) 9874 9777
Australian Huntington’s Disease Association - QLD
385 Ipswich Road, Annereley QLD 4103
Tel (07) 3391 8833
Huntington's Victoria - VIC
16 Wakefield Street, Hawthorn VIC 3122
Tel (03) 9818 6333
Huntington’s Disease Society of America
Read More at Virtual Medical Centre
Reviewed by Dr Elizabeth McCusker, Neurologist, Westmead Hospital, Australia