Association of the CYP17 gene and CYP19 gene polymorphisms with risk of endometriosis in Japanese women

BACKGROUND: To investigate whether polymorphisms of CYP17 and CYP19 genes are associated with the risk of endometriosis, we analysed the frequency and distribution of a single nucleotide polymorphism at the 5' untranslated region of the CYP17 gene, and a tetranucleotide (TTTA) tandem repeat polymorphism and a 3 bp insertion (I)/deletion (D) polymorphism in intron 4 of the CYP19 gene. METHODS: We studied 140 patients with endometriosis, 67 with adenomyosis and/or leiomyomas and 177 healthy control women. RESULTS: The distribution of the genotypes of CYP17 and alleles of the TTTA repeat polymorphism of CYP19 were not significantly different between the groups. In contrast, an increased frequency of the D/D genotype was observed in the endometriosis group as compared with the control group (D/D genotype versus I/I plus I/D genotypes; corrected P = 0.024). This was more evident in the endometriosis subgroups with chocolate cysts (corrected P = 0.043) and at severe clinical stages (corrected P = 0.035). CONCLUSIONS: The results suggest that the 3 bp I/D polymorphism of the CYP19 gene may be weakly associated with the susceptibility of endometriosis in a Japanese population.