Through simple observation, we know that, on average, men have a shorter life expectancy than women. Statistically speaking, both the occurrence of cancer and the mortality rate from disease is higher in men than in women. Now science may be able to correctly explain why that is. A recent study has found that the male Y chromosome may somehow be connected to a shorter lifespan. Scientists have specifically linked the Y chromosome to increased chances of cancer and higher mortality from the disease.
Researchers from Uppsala University in Sweden analyzed the DNA in blood samples from more than 1,600 elderly men, looking for genetic alterations. These alterations in the DNA of normal cells accumulate throughout our lives and have been linked to diseases such as cancer and diabetes. According to the press release, the most common genetic alteration in DNA of the elderly men was the loss of the Y chromosome in a proportion of the white blood cells. After following the health of these men for many years, researchers concluded that there was a link between the loss of the Y chromosome and a shorter lifespan. “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,” Lars Forsberg, lead researcher of the study, explained in the press release.
Most human cells contain 23 sets of chromosomes, including one pair of sex chromosomes. The Y chromosome is only present in males. This gives males the iconic sex chromosome set of XY, while women have XX. The Y chromosome triggers the development of male testes and hormones in the embryo. Loss of the Y chromosome in males is a relatively common occurrence that is associated both with illness and old age. The Y chromosome, which is much smaller than the X, was previously believed to not contain much genetic information. Researchers are beginning to realize 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,” Professor Jan Dumanski, another researcher from the study, explained in a press release.
Researchers now believe that the Y chromosome may have a role in tumor suppression. This may explain why men are more likely to get cancer than women. Not all is bleak for men, however. “We believe that analyses of the Y chromosome could in the future become a useful general marker to predict the risk for men to develop cancer,” Dumanski concluded.
Source: Forsberg LA, Rasi C, Malmqvist N, et al. Mosaic loss of chromosome Y in peripheral blood is assoaciated with shorter survival and higher risk of cancer. Nature Genetics. 2014.