Loss of Y chromosome is linked to higher cancer risk and shorter life expectancy in men, a new study from Sweden shows.
The Y-chromosome is one of the two sex chromosomes in human beings (the other one being the X chromosome). The chromosome is passed down only among males and has 59 million building blocks of DNA.
As men get older, they begin losing the Y chromosome from some of their cells. The loss of Y was considered as normal. However, a new study from Uppsala University in Sweden has found that the loss of the male-sex chromosome increases cancer risk and is associated with early death.
On average, women live at least six to eight years longer than men. By age 85, there are about six women for every four men.
For the study, researchers analyzed blood samples from 1,600 elderly men. The team found that the most common genetic change in the sample was loss of the Y chromosome.
Researchers then followed the study participants to see if there was a link between Y chromosome loss and shorter survival.
"Men who had lost the Y chromosome in a large proportion of their blood cells had a lower survival, irrespective of cause of death. We could also detect a correlation between loss of the Y chromosome and risk of cancer mortality," said Lars Forsberg, researcher at the Department of Immunology, Genetics and Pathology, Uppsala University, lead author of the study, according to a news release.
Previously, researchers believed that the Y chromosome was only associated with male sex determination. A related study on Y chromosome found that it has remained stable in the past 25 million years and that it affects several types of cells in the body and not just the sexual organs. In fact, the Y chromosome currently has an "elite set" of genes that are crucial for human survival, researchers say.
"You have probably heard before that the Y chromosome is small, insignificant and contains very little genetic information. This is not true. Our results indicate that the Y chromosome has a role in tumour suppression and they might explain why men get cancer more often than women," said Jan Dumanski, professor at the Department of Immunology, Genetics and Pathology, Uppsala University.
Analyzing the Y chromosome could help scientists assess the risk of cancer in men, Dumanski added.
The study is published in the journal Nature Genetics.