1. Huntington’s Chorea
Learning Objective – to know that Huntington’s is inherited via a dominant allele and the symptoms of the disease.

3. What is Huntington’s disease?
Huntington’s disease, sometimes called Huntington’s chorea, is a rare and fatal inherited disease of the central nervous system.
Huntington’s disease is caused by a single dominant allele, which means that heterozygous individuals will develop the disease.
The disease causes damage to brain cells, leading to a gradual loss of co-ordination, decline in mental ability and changes in personality.
Around 4,800 people in the UK have Huntington’s disease.

4. The symptoms of Huntington’s disease
Symptoms of Huntington’s disease usually begin to develop between the ages of 30 and 50, although they can appear earlier in rare occasions.
Early symptoms include:
twitching, clumsiness and stumbling
lack of concentration and memory loss
depression and mood changes
Teacher notes
As the disease progresses, constant nursing care is needed. The cause of death in people with Huntington’s disease is often a secondary illnesses such as pneumonia.
Huntington’s disease is incurable, but medication can help to reduce the symptoms. However, as the disease progresses, the person’s co-ordination and movement becomes worse, and their mental abilities decline further.

5. The inheritance of Huntington’s disease

6. Patterns of inheritance: Huntington’s