The X Factor in Health: How sex chromosomes shape disease and drug responses
A Nature feature shows that the X and Y chromosomes influence health beyond hormones. Some X-linked genes escape inactivation, driving sex differences in autoimmunity, cancer, cardiovascular and neurodevelopmental conditions; in mice, the statin side effects were linked to an Xi escape gene, Kdm5c, with DHA supplementation partially reversing the metabolic effects. Overall, Xi and Y gene expression affect about 21% of genes in tested cells, underscoring the need to study XX versus XY biology to understand disease risk and drug responses.