Infertility: that of men could be caused by mutations of the X chromosome
A new international study has suggested that infertility in men could be caused by mutations on the X chromosome. Researchers have found at least 50 varieties of genes on this chromosome, which can lead to one reduced sperm production. Nearly half of men with this condition have no medical explanation for their infertility.
In recent years, studies have identified three X chromosome genes that could be the cause of poor sperm production. However, a further study by the University of Florence asked whether there might be other genes on this chromosome that could play a role in all of this.
X chromosome, their mutations could lead to male infertility
The team of researchers analyzed samples from over 2,400 people with low sperm counts, comparing them to those of people with normal sperm production. For now, no samples of transgender or non-binary people have been introduced into the study. People came from all over Europe with different ages and ethnicities. Before participating in the study, their doctors had not found no cause for this condition.
This analysis suggested the presence of a large number of mutated genes from infertile men, including the three genes already mentioned from previous studies. Through further investigation, scientists have discovered as many as 21 genes, which could be the main cause of this condition. In addition to these genes there should be 34 in which mutations can lead to male infertility. Most of the mutations in these genes affected the way testicular cells they divide to form sperm, and researchers have repeatedly found them in these men, as well as some sterile male flies and mice.
Since people assigned to be male at birth inherit an X chromosome from the mother and a Y chromosome from the father, this means that sperm-related infertility could be passed from mothers to children. However, the mutations could also occur spontaneously during the development of the egg or embryo. As we can imagine, many think that the X chromosome is purely female, as they have two. No one would have ever expected it to be part of male reproduction.
In most cases, genetic mutations lead to a low sperm count, therefore it is still possible that these men have children and pass the mutation on to their daughters. The daughters would then have a 50/50 chance of passing the mutation on to their offspring, depending on the X chromosome they pass on. With a better understanding of the mutations that cause infertility, doctors may be able to use genetic testing to diagnose causes low sperm count and choose the most appropriate treatments.
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