The Y chromosome and its impact on health and disease.

The Y chromosome is the most gene-deficient chromosome in the human genome (though not the smallest chromosome), and has largely been sequestered away from large-scale studies of the effects of genetics on human health. Here I review the literature, focusing on the last two years, for recent evidence of the role of the Y chromosome in protecting from or contributing to disease. While many studies have focused on Y chromosome gene copy number and variants in fertility, the role of the Y chromosome in human health is now known to extend to many other conditions including the development of multiple cancers and Alzheimer's disease. I further include discussion of current technology and methods for analyzing Y chromosome variation. The true role of the Y chromosome, and associated genetic variants, in human disease will only become clear when the Y chromosome is integrated into larger studies of human genetic variation, rather than being analyzed in isolation.