Female Chromosomes Offer Resilience to Alzheimer's

Women with Alzheimer's live longer than men with the disease while suffering less severe effects in the early stages, and a study in Science Translational Medicine says this predisposition is common in both humans and mice because they have genetic protection, reports Medical Xpress . Women's second X chromosome grants two "doses" of a protective protein from a gene, KDM6A, that only exists on this chromosome. Certain individuals, both male and female, have an especially potent variant of this gene with added protection — but women have two copies of KDM6A. About 13 percent of women and 7 percent of men around the world have this variant. A review of studies of older people, many of whom already had mild cognitive impairment, showed women with one or two copies of the variant appeared to progress more slowly toward Alzheimer's. Gene expression analyses indicated that women overall had more KDM6A protein in their brains than men, and that people with Alzheimer's had more of the protein in brain regions that are harmed early. "This protective mechanism on the X chromosome opens the possibility that we could increase resilience to Alzheimer's and other neurodegenerative disorders by boosting KDM6A or other X factors in both men and women," said Professor Dena Dubal at the University of California, San Francisco.