Infertile men may have a gene defect that takes away a protein that cloaks and protects sperm against a woman’s immune system while traveling to the egg, according to a study that offers a new explanation for some male infertility. Although the sperm from men with the gene variant look normal under a microscope, they are less able to move through a solution made to resemble human cervical mucus, researchers reported today in Science Translational Medicine. When the cloaking protein was added to the sperm, they regained their swimming abilities, the study found. About 10 percent of women of childbearing age have difficulty getting pregnant, and one in three cases involves male infertility, according to the National Institutes of Health. In another third of cases, the cause of infertility isn’t known. The discovery announced today may aid in those cases, the authors of the study wrote.
