Male infertility possibly linked to missing protein

A study published in the journal of Science Translational Medicine, believes it has found a potential cause for a number of unexplained cases of male infertility.

The absence of a protein that coats sperm and allows them to attach to an egg can be missing in some men due to faulty genes. The study shows how men with two copies of the defective gene cannot produce the protein that coats their sperm.

The study looked at around 500 Chinese couples who were trying to become pregnant. The scientists found that men who had two copies of the abnormal gene were 30 percent less likely to father a child over a two-year period, compared to those who didn't.

Couples who had babies over the course of the study also showed some interesting results. Men that had the abnormal gene were still able to conceive with their partners, but around two months later then those with healthy genes.

However, the abnormal gene is actually found in around a quarter of all men but factors including size and speed of the sperm allow some men to reproduce as normal.

Some fertility experts said the research into the gene DEFB126 was too preliminary to prove that the mutation affects couples’ ability to conceive.

Since some Chinese couples “were able to achieve pregnancy on their own — it was just taking a longer time,” said Dolores Lamb, professor of urology at Baylor College of Medicine and president-elect for the American Society of Reproductive Medicine. Couples “could simply be told to maybe wait a little longer than a year.”