Huntington’s disease

- Huntington’s disease is a degenerative disease of the nervous system - The disease has no obvious phenotypic effects until the individual is about 35 to 40 years of age​ - Once the deterioration of the nervous system begins, the condition is irreversible and fatal​ - The timing of onset of a disease significantly affects its inheritance​ - There is a test that can detect the presence of the Huntington’s allele in an individual’s genome​ - Some individuals with a family history of Huntington’s disease choose to be tested for the allele​ - Others decide that it would be too stressful to find out​