A defective protein gene in sperm could be responsible for a significant proportion of male infertility, according to a new study published in the journal Science Translational Medicine.
This particular protein – called DEFB126 – usually coats the sperm and protects it from the female immune system, allowing it to reach the egg.
Researchers at the University of California’s UC Davis campus have discovered, however, that as many as 50 percent of men have one defective DEFB126 gene and up to a quarter could have two defective genes, which might explain a significant number of cases of male infertility.
"In 70 percent of men, you can’t explain their infertility on the basis of sperm count and quality," said senior author Gary Cherr.
The researchers now hope the discovery could be used to develop a test for the defective gene, which would allow infertile couples to undergo a directed treatment where the sperm is injected directly into the egg – avoiding expensive workarounds to rule out other causes.