Jun 23, 2026 07:00:00

Men lose their Y chromosome as they age, but are there any disadvantages to this?

The Y chromosome is a type of sex chromosome, and in humans, only males are born with both an X and a Y chromosome, while females are born with only an X chromosome. However, it turns out that men gradually lose their Y chromosome as they age, and the science media outlet ScienceAlert has published an article explaining the 'disadvantages of men losing their Y chromosome.'

Men Can Lose Their Y Chromosome With Age, And We Finally Know The Cost : ScienceAlert
https://www.sciencealert.com/men-can-lose-their-y-chromosome-with-age-and-we-finally-know-the-cost

Throughout human evolution, the number of genes on the Y chromosome has decreased at an astonishing rate, and evolutionary biologist Jenny Graves suggests that the Y chromosome will disappear in the near future, within 5 million years. It has already been found that some spiny rats have lost their Y chromosome , and that other chromosomes have begun to take over the function of the Y chromosome in their bodies.

Are men destined to become extinct? What does the disappearing Y chromosome signify? - GIGAZINE

However, the Y chromosome, which is found in men's blood, brain, and immune cells, can disappear with age. Studies have shown that about 40% of men at age 70 show loss of Y chromosomes in their blood, and that percentage reaches about 57% by age 93.

The Y chromosome is known to be essential for sex determination and sperm function, but historically it was thought to have few other functions. For a long time, age-related Y chromosome loss was thought to be a benign marker of aging.

However, recent new genetic evidence suggests that the loss of the Y chromosome in certain cells may be associated with increased mortality risk and disease. For example, a 2022 study reported that a Y chromosome deficiency in specific immune cells in the heart of mice led to increased cardiovascular dysfunction and mortality.

Further studies have shown that older men with Y chromosome deletions have an increased risk of premature death and cancer. Although Y chromosome deletions are rare in younger people, they have also been linked to infertility and developmental disorders.

A 2023 study found that up to 40% of older men with bladder cancer had little to no Y chromosomes in their tumor cells. Men are up to five times more likely to develop bladder cancer than women, leading some researchers to believe that the Y chromosome may play some role in bladder cancer.

Preliminary studies support this hypothesis, with a 2025 study revealing that immune cells lacking a Y chromosome have a reduced ability to attack cancer cells. Another paper published the same year concluded that 'the loss of the Y chromosome is likely to affect the male immune system.'

Research into male Y chromosome loss is still in its early stages, but initial findings suggest that the Y chromosome may be involved in far more cellular functions than previously thought. Jennifer Hughes, an evolutionary biologist at MIT, told ScienceAlert, 'The genes held on the Y chromosome play vital roles throughout the body, so the selective pressure to maintain those genes is very strong, and they are unlikely to be lost.'

On the other hand, Graves, who advocates the theory that the Y chromosome will disappear within 5 million years, points out that spiny rats and other animals have been able to replace the function of the Y chromosome with that of other chromosomes without any problems. He argues that it is possible that the Y chromosome could similarly be replaced by other chromosomes in humans.