Objective: To investigate whether polymorphisms in genes involved in biosynthesis and signalling of sex steroids influence susceptibility to endometriosis and to infertility associated with it.
Materials and methods: Patients with endometriosis (n = 150) and fertile controls (n = 199) were genotyped for polymorphisms in oestrogen receptor genes ESR1 (rs2234693 - T/C single nucleotide polymorphism (SNP), dinucleotide (TA)(n) repeat) and ESR2 (dinucleotide (CA)(n) repeat), progesterone receptor gene PGR (rs10895068 - G/A SNP, 306-bp Alu-insertion), 17β-hydroxysteroid dehydrogenase type 1 gene HSD17B1 (rs605059 - A/G SNP), and aromatase gene CYP19A1 (rs10046 - C/T SNP, (TTTA)(n) tetranucleotide repeat, 3-bp TCT insertion/deletion polymorphism).
Results: The HSD17B1 A/G SNP A allele increased overall endometriosis risk and the risk of stage I-II disease, while ESR1 longer (TA)(n) repeats only correlated with susceptibility to stage I-II endometriosis. When considering patients' fertility status, HSD17B1 A/G SNP A allele and ESR1 longer (TA)(n) repeats were associated with endometriosis accompanied by infertility, while ESR2 shorter (CA)(n) repeats were linked with endometriosis without infertility. Other polymorphisms were distributed similarly among patients and controls.
Conclusions: Genetic variants in ESR1, ESR2, and HSD17B1 genes could modify susceptibility to endometriosis and might influence the fertility status in endometriosis patients.