HUNTINGTON'S DISEASE - A BRIEF INTRODUCTION

Huntington's Disease is named after George Huntington, who first described it in 1872.

It is a rare condition, with an annual incidence (new cases) of 0.5 per 100,000, and a point prevalence of 6 per 100,000. It is transmitted by autosomal dominant inheritance - each child of an affected parent has a 50 per cent chance of getting the disease. The abnormal gene is on chromosome 4. The main pathological changes are brain atrophy, and overactivity of the dopamine mechanism, due to reduction of GABA synthesising enzymes

The age of onset is usually 30 to 50 years of age, although it can occur at any age. The main clinical features are chorea (involuntary movements) and dementia. The disease is relatively progressive with increasing disabilities. First symptoms may be involuntary movements, awkward gait, and increased falling, followed by loss of co-ordination, dementia, loss of speech, and difficulty in swallowing. Death is commonly caused by choking or pneumonia.

There is no cure, but choreiform movements may be relieved by phenothiazines. Considerable support from local services, home nursing resources for long-term care, and supply of disability aids, is available for families of the sufferer. Genetic and general counselling of the family is essential, because of the high risk of inheriting the gene .