6 quick facts about Huntington's brain disease

• 1. Huntington's is caused by an error in a section of DNA called the huntingtin gene.
  

2. This contains the instructions for making a protein, called huntingtin, which is vital for brain development

3. Huntington's generally affects people in their prime - in their 30s and 40s

4. Patients affected by this disease die around 10 to 20 years after symptoms start

5. About 8,500 people in the UK have Huntington's and a further 25,000 will develop it when they are older

6. A genetic error corrupts the protein and turns it into a killer of brain cells.