Huntington's Disease Is Caused by a Single Dominant Allele and Results

Essay

Huntington's disease is caused by a single dominant allele and results in progressive mental and neurological damage. The disease usually becomes symptomatic when a person is between 30 and 50 years old and the patient usually dies within 15 years of diagnosis. Approximately 1 in 25,000 Caucasians have this disease. Huntington's disease has not been associated with any other disease, now or in the past. Why might natural selection not have eliminated such a deleterious gene from the population?