In addition to its effect on fertility, earlier menopause has other deleterious effects on women such as an increased risk for osteoporosis, osteoarthritis and cardiovascular disease, while it has a protective effect on the risk of breast cancer. The age of menopause varies greatly among Caucasian women, ranging between 40 and 60 year of age, with an average at around 50. The reasons for this variation are unknown, but there is evidence from studies of twins that this could be due to inheritable genetic factors. However, until now, GWAS had not been used to study the effect of genetic variants on age at menopause.

The scientists intend to follow up their work with an even larger sample of menopausal women to identify more chromosomal loci. "GWAS gives you SNPs connected with menopausal age, and a possible indication of the gene involved, but not a total proof of function", said Ms Stolk. "When we have a larger group of loci we intend to perform functional studies to study the exact biology and effect of this association."

The scientists say that it may be several year before they have enough information to make genotyping for earlier menopause available to patients, and even then this may not be helpful to all women with fertility problems. "However, if these studies give us a better understanding of the function of the genetic variants involved in early menopause, we might one day be able to screen women who have problems getting pregnant to see if they have one or more of these variants which might relate to their sub-fertility, and perhaps interfere with the relevant physiological pathways in order to delay their total infertility", said Ms Stolk.

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