Gene clues to male infertility and testicular cancer

Research in mice has yielded another possible genetic explanation for male infertility and a link to testicular cancer. A team led by Haifan Lin, a professor of cell biology at Duke University Medical Center, US, has discovered that a gene in mice - called miwi - is linked to infertility. The study is published in the journal Developmental Cell.

Miwi comes from a family of genes associated with the division of reproductive stem cells, immature cells that can develop into adult sperm cells. When the miwi gene is missing or defective, mice are often completely sterile. Although no human tests have yet taken place, the study authors believe that the human equivalent - hiwi - will be linked to infertility in men. The Duke study could eventually lead to genetic testing for the hiwi gene.

In a related paper, hiwi is linked to testicular cancer. In a paper published in the journal Oncogene, Lin and his research team show that men who inherit an overactive form of the hiwi gene have a higher risk of testicular cancer, particularly a version called seminoma, which affects the reproductive cells. The researchers found that seminoma tumours had reproductive cells containing hiwi that was up to 16 times more active than is normal. Twelve out of 19 patients studied showed evidence of an overactive hiwi gene.