Mutant alleles of HD improve the life span of p53−/− mice

Loss of function mutations in the p53 tumor suppressor gene predispose mice and humans to cancer, resulting in abbreviated life spans. A dominant mutation in the murine HD gene, similar to mutations that cause Huntington's disease in humans, reverses some of the effects of p53 mutations on longevity. We attribute this to the enhanced apoptotic effect of the expanded polyglutamine region in the HD protein on proliferating cells lacking p53.