The genotype associated with the lowest pregnancy rate (heterozygous-normal/low) was also associated with increased measures of autoimmunity. Women with this genotype also had a higher incidence of polycystic ovary syndrome (a common cause of infertility), which is thought to have an autoimmune component. "Previous studies have suggested that autoimmunity plays a role in infertility," said Dr. Barad. "Now, for the first time, we have a potential genetic mechanism that underlies several different threats to infertility."

The cost of the blood test for the FMR1 should be relatively low - comparable to screening tests for Tay-Sachs and other genetic diseases. While the FMR1 gene test is not yet clinically available, "It's likely that the findings will lead to clinical applications in the future," said Dr. Barad.

"Any test that is proven to have predictive value for a woman's fertility would give her a heads up in terms of planning a family," he added. "For instance, if a woman planning to go to law school or medical school learns she has a certain amount of risk of losing her ovarian function before she is 35, she may choose to bank her eggs or try having children at an earlier age, rather than delay."

Dr. Barad's paper, "FMR1 Genotype with Autoimmunity-Associated Polycystic Ovary-Like Phenotype and Decreased Pregnancy Chance," was published in the December 2010 issue of the online journal PLoS One. The other senior author is Norbert Gleicher, M.D., of Yale School of Medicine and CHR.

Source: Albert Einstein College of Medicine