FMR1 and primary ovarian failure: Fragile X-associated primary ovarian insufficiency (FXPOI) is among the family of disorders caused by the expansion of a CGG repeat sequence located in the 5' untranslated region (UTR) of the X-linked gene FMR1. About 20% of women who carry an allele with 55 to 200 unmethylated CGG repeats, called the premutation (PM) allele, develop hypergonadotropic hypogonadism and cease menstruating before age 40, a condition also known as premature ovarian failure (POF).