Predictors and risk model development for menopausal age in fragile X premutation carriers

PURPOSE: Women who carry a fragile X mental retardation 1 premutation are at risk for fragile X-associated primary ovarian insufficiency and should be counseled for a potentially reduced fertility. Multiple factors can affect the age of onset and severity of fragile X-associated primary ovarian insufficiency. In this study, we assessed the predictive power of several factors with menopausal age, a surrogate measure of onset of fragile X-associated primary ovarian insufficiency. METHODS: Genetic, environmental, and reproductive factors were analyzed by Cox proportional hazard models in 1068 women, 385 of fragile X families ascertained through the Nijmegen study and 683 of fragile X families or general population families ascertained through the Atlanta study. RESULTS: The highest association with menopausal age among fragile X mental retardation 1 premutation carriers was found for risk index by CGG repeat size (hazard ratio, 1.43) and smoking (hazard ratio, 1.34). Women from the Nijmegen cohort showed an overall lower age at menopause onset, for which a correction was made. A prediction model based on these two parameters, mean menopausal age of first-degree relatives with the same mutation status and the correction for ascertainment site, estimated the probability of becoming postmenopausal for premutation carriers, with a margin of 7-10%. CONCLUSION: We conclude that this model serves as a first step toward clinical application of fragile X-associated primary ovarian insufficiency prediction