It has long been known that men have a shorter life expectancy than women. Now, a new study finds that loss of the Y chromosome (LOY) in blood cells may be to blame for this discrepancy between the sexes. What’s more, loss of this chromosome may also lead to a higher mortality from cancer.
The study, published in Nature Genetics, was the result of work conducted by four Swedish universities. The collaboration, dubbed Scifelab, included scientists from Karolinska Institutet, KTH Royal Institute of Technology, Stockholm University, and Uppsala University.
Emphasizing that although changes in the DNA of normal cells gather during our lives and have been linked to cancer and diabetes, the risk factors behind the differences in life expectancies have not been known, according to the researchers. Prior to their study, chromosome Y was mostly associated with sex determination and sperm production.
For the study, the researchers analyzed the DNA in blood samples from a group of more than 1,600 elderly men. After studying the group of men for up to 20 years, the researchers found that the most common genetic alteration was an LOY in a proportion of the white blood cells. The researchers also discovered a correlation between LOY and shorter survival, irrespective of cause of death.
Development of Future Therapies
Commenting on the study’s findings, Jan P. Dumanski, professor in the Department of Immunology, Genetics and Pathology at Uppsala University, told Healthline, “We believe this is just a beginning of understanding why men live, on average, shorter lives than women and what is the role of human chromosome Y in this context. These finding may have broad implications for prediction of healthy aging in men, and possibly also for development of future therapies based on understanding the molecular mechanism behind loss of chromosome in various cells.”
Four Times Greater Risk of Death from Cancer
When contacted by Healthline, lead study author, Lars Forsberg, Ph.D., a researcher at the Department of Immunology, Genetics and Pathology at Uppsala University, said, “The men who had lost the Y chromosome in a high degree of their blood cells at the time of taking the blood samples, had an almost four times greater risk of death from cancer in any organ of the body, as compared to men with no detectable loss of Y cells at the time of blood sampling.”
Emphasizing that the Y chromosome is believed to be small and insignificant, and holding very little genetic information, Dumanski said in a press statement, “This is not true. Our results indicate that the Y chromosome has a role in tumor suppression, and they might explain why men get cancer more often than women."
Looking to the future, the researchers believe that further analyses of the Y chromosome could become a useful general marker to predict men’s risk for developing cancer.