Female chromosomes offer resilience to Alzheimer's: Study reveals that females' second X chromosome…

Women live longer than men with Alzheimer’s because their sex chromosomes give them genetic protection from the ravages of the disease. Women get two ‘doses’ of a gene that only exists on the X chromosome. And some people, both male and female, have an especially potent variant of this gene. Long-term studies of older people, many of whom already had mild cognitive impairment, showed women with one or two copies of the variant progressed more slowly toward Alzheimer’s. Women with Alzheimer’s live longer than men with the disease, and scientists at UC San Francisco now have evidence from research in both humans and mice that this is because they have genetic protection from the ravages of the disease.