Wellcome Sanger Institute study could lead to improvement in male infertility diagnosis
A genetic study could lead to improvements in the diagnosis and management of male infertility.
Scientists at the Wellcome Sanger Institute and University of Tartu discovered a genetic variant linked to the issue.
They found a common subtype of Y chromosome that increases the carrier’s risk of fertility issues in a substantial proportion of men of European ancestry.
Men with this had significantly increased risk for genetic mutations affecting the sperm production process, known as spermatogenesis, and can be almost nine times more likely to have fertility issues.
The work - the largest genetic study to date looking at unexplained infertility in men - indicates that monitoring for this genetic variant could identify those at higher risk in their early adulthood, aiding diagnosis and family planning decisions.
Dr Pille Hallast, co-author and Senior Staff Scientist at the University of Tartu and the Wellcome Sanger Institute, said: “Our study is the largest, most sophisticated look at the genetic variation of this particular Y-chromosomal region that can increase the risk of impaired sperm production in men. By having access to such a large number of patients and reference men, and being able to compare their genetic data to andrological information, we identified a common Y-chromosome subtype that is susceptible to genetic changes leading to low sperm count, but also can go unnoticed and passed down in families until a deletion in this genomic region occurs.”
Professor Maris Laan, senior co-author and professor of human genetics at the Institute of Biomedicine and Translational Medicine at the University of Tartu in Estonia, said: “Being able to identify the genetic reason for these men having impaired sperm production will help give them a diagnosis and access to the support that this brings.
“While some deletions on the Y chromosome were previously known to interfere with sperm production, understanding at this level of detail is important for the management of male fertility issues, and in this case the options of having children early in life or preserving sperm for later use could be discussed.”
Dr Chris Tyler-Smith, senior co-author and former senior group leader at the Wellcome Sanger Institute, said: “The biggest surprise is that a Y chromosome subtype with such a deleterious effect on fertility is present in the population at all.
“Why hasn’t it disappeared if it is so harmful? Has it perhaps only started to have this effect on fertility recently, as sperm counts have declined for environmental reasons in the last few decades and resulted in a detrimental combination of genetics and environment?”