RESUMEN
PURPOSE: Approximately 20-30% of women with an FMR1 premutation experience fragile X-associated primary ovarian insufficiency (FXPOI); however, current risk estimates based on repeat size only identify women with the midrange of repeats to be at the highest risk. METHODS: To better understand the risk by repeat size, we collected self-reported reproductive histories on 1,668 women and divided them into high-resolution repeat size bins of ~5 CGG repeats to determine a more accurate risk for FXPOI in relation to CGG repeat length. RESULTS: As previously reported, women with 70-100 CGG repeats were at the highest risk for FXPOI using various statistical models to compare average age at menopause and risk of FXPOI, with women with 85-89 repeats being at the highest risk. Importantly, women with <65 repeats or >120 repeats did not have a significantly increased risk for FXPOI compared to women with <45 repeats. CONCLUSION: Using a large cross-section study on 1,668 women, we have provided more personalized risk assessment for FXPOI using high-resolution repeat size bins. Understanding the variability in risk has important implications for family planning and overall health among women with a premutation.