The frequency of heterozygote carriers of (risk zone, alleles of FMR1 gene (40-47 CGG-repeats) was significantly higher in group of patients with ovarian dysfunction than in control group I. The tendency for higher frequency of those alleles was observed in patients with "poor response" to superovulation induction in IVF cycles. The average number of oocytes and follicles, which was obtained after stimulation of superovulation, was significantly decreased in FMR1 gene "risk zone" alleles carriers compared to patients with normal alleles of FMR1 gene. The average general dosage of exogenous gonadotrophin, necessary for superovulation induction was significantly higher in heterozygote carriers of FMR1 gene "risk zone" alleles than in patients with normal genotype. Thereby, the FMR1 gene "risk zone" alleles can be one of the hereditary susceptibility factors of impairment nature and stimulated ovulation.