Gene Mutation May Be Linked to Male Infertility
Study May Lead to New Ways of Treating Infertility in Men
Seeking Causes of Infertility continued...
"These fertility values were about the same for men in our study, regardless of whether they possessed the normal or mutated gene," he says. "So looking at these sperm in conventional ways -- which is the way men would be evaluated in fertility clinics -- you would have no reason to think that many of the men with the genetic mutation would have reduced sperm function and a potential problem with fertility."
Tollner says identifying men with the mutation may prove to be a better indicator of male infertility than currently used measures.
Identifying Men With Genetic Mutation
The group's effort to confirm that the mutation contributes to infertility took them to Anhui, China.
A team led by Scott Venners and colleagues from British Columbia's Simon Fraser University examined the sperm of 500 newly married men whose wives were trying to conceive, and they then followed the couples for almost two years.
The birth rate among couples in which the man carried two copies of the defective DEFB126 gene was found to be 30% lower than the other couples in the study.
Study co-researcher Gary Cherr, PhD, of the University of California, Davis, says once the clinical significance of the finding is confirmed, identifying men with the double mutation should not be difficult. He says an at-home test kit could be developed to help couples avoid expensive clinical testing.
In an editorial published with the study, gene researcher Steve Rosen, PhD, of Duke NUS Medical School in Singapore, writes that it is too soon to predict how the mutation's discovery will affect infertility screening and treatment.
"It is clear that this genetic information could lead to more informed assisted reproduction in addition to possible new methods of treating sperm," he writes. "In the meantime, we eagerly await a more complete understanding of the epidemiology of the DEFB126 [mutation] and of the mechanisms by which it increases time to pregnancy."