Most dominantly-inherited disease genes have been lost from…
Most dominantly-inherited disease genes have been lost from the gene pool over time. Read the following information about Huntington’s disease. Why would a disease gene like HTT, which causes Huntington’s disease, not be subject to the same kind of evolutionary pressure that you would expect for a dominantly-inherited disorder? From Online Mendelian Inheritance in Man: The classic signs of Huntington disease are progressive chorea (tremors), rigidity, and dementia. Typically, there is a…phase of mild psychotic and behavioral symptoms which precedes frank chorea by up to 10 years. Chandler et al. (1960) observed that the age of onset was between 30 and 40 years. The disease terminated in death on average 17 years after manifestation of the first symptoms.