A variation in a gene involved in regulating cholesterol in the bloodstream also appears to affect progesterone production in women, making it a likely culprit in a substantial number of cases of their infertility, a new study from Johns Hopkins University researchers suggests.
The Hopkins group has also developed a simple blood test for this variation of the scavenger receptor class B type 1 gene ( SCARB1) but emphasized there is no approved therapy yet to address the problem in infertile women.
Following up studies in female mice that first linked a deficiency in these receptors for HDL -- the so-called "good" or " healthy" cholesterol -- and infertility, researchers report finding the same link in studies of women with a history of infertility.
The findings has been published on-line this week in the journal Human Reproduction.
If the new study's findings hold up on further investigation, the John Hopkins team says they not only will offer clues into a genetic cause of some infertility, but could also lead to a treatment already shown to work in mice.
"Infertility is fairly common and a lot of the reasons for it are still unknown," warns endocrinologist Annabelle Rodriguez, an associate professor of medicine at the Johns Hopkins University School of Medicine and the lead author. "Right now, the benefit of this research is in knowing that there might be a genetic reason for why some women have difficulty getting pregnant. In the future, we hope this knowledge can be translated into a cure for this type of infertility."