Comparison of ovarian FMR1 genotypes and sub-genotypes in oocyte donors and infertile women

We recently described ovarian genotypes and sub-genotypes of the FMR1 gene with distinctly associated ovarian aging patterns, which in infertile women follow a typical X-linked distribution pattern. Whether normally fertile women, however, also demonstrate the same distribution, is unknown. We, therefore, investigated ovarian FMR1 genotype and sub-genotype distribution in 182 oocyte donor candidates in comparison to 339 infertile controls. As previously reported, genotype designation was made, based on a normal range of CGG (n = 26-34) (median 30), defining women as normal (norm), heterozygous (het) or homozygous (hom). Het and hom genotypes were further subdivided into sub-genotypes, based on whether abnormal alleles were above (high) or below normal range (low). Oocyte donors presented with 47.8% norm, 45.1% het and 7.1% hom genotypes, confirming a typical X-linked distribution pattern. They, however, still subtly differed from infertility patients, especially in het sub-genotypes. These findings validate recently newly described ovarian genotypes and sub-genotypes, reaffirming their relevance to female fertility/infertility.