Introduction. Endometriosis is a common gynecological disease that has important socio-economic significance for both sick women, their families, and society as a whole. It is often combined with other hyperplastic diseases of the uterus.Aim. To analyze the involvement of GWAS-significant polymorphic loci of sex hormone genes in the development of combined proliferative diseases of the uterus in women with endometriosis. Materials and methods. The sample for the study included 395 women, including 103 patients with isolated endometriosis and 292 patients with endometriosis in combination with uterine fibroids and/or endometrial hyperplasia. All women underwent molecular genetic testing of seven GWAS-significant single-nucleotide polymorphic variants of sex hormone genes (rs34670419, rs11031005, rs11031002, rs148982377, rs112295236, rs1641549, rs117585797). The analysis of associations of polymorphic variants with the risk of developing combined proliferative diseases of the uterus in patients with endometriosis was carried out. To assess the functional effects of SNP associated with the formation of combined proliferative diseases of the uterus in women with endometriosis, the online programs HaploReg and Gtex Portal were used.Results and discussion. Genetic variant A rs117585797 of the ANO2 gene is a risk factor for the development of combined proliferative diseases of the uterus in women with endometriosis (p = 0.05, рperm = 0.05, OR = 4.29). According to the data obtained in silico, the rs117585797 locus localized in the intron of the ANO2 gene affects the affinity of the regulatory DNA motif to the transcription factors Crx and Gsc.Conclusions. Polymorphic locus rs117585797 of the ANO2 gene is associated with a high risk of the formation of combined proliferative diseases of the uterus in patients with endometriosis.