Polymorphisms of Estrogen Receptor-α and Estrogen Receptor-β Genes and its Expression in Endometriosis

Endometriosis is a common gynecological disorder, characterized by the presence of endometrial-like tissue in the extrauterine location. The increasing estradiol concentration can influence endometriosis risk and estrogen receptor (ER) activity. Polymorphism in ER causes gene expression alteration and influences hormone-receptor interaction. This research aims to determine ER genetic polymorphisms in endometriosis pathogenesis.

This study was performed on case-control polymorphisms, which compared 83 women with endometriosis and 76 women without endometriosis. However, the samples used for ER gene expression analysis and estrogen level measurement were obtained from 18 women with endometriosis and 18 women without endometriosis. Polymerase chain reaction-restriction fragment length polymorphism was used to determine ER genetic polymorphisms. Chi-square, Mann-Whitney test, Spearman's correlation (p), t-independent, and two-tailed tests were used to analyze the data.

Association between the allele ERα rs9340799 A/G and endometriosis was significantly different (p=0.012), whereas rs2234693 T/C polymorphism showed no association with endometriosis. The correlation between the genotype frequencies of allele ERβ rs4986938 G/A and endometriosis was found significantly different (p=0.015; p=0.034).

Estradiol level and ERβ expression increases, polymorphism genotypes and alleles of ERβ rs4986938 G/A gene and allele frequency of ERα rs9340799 A/G gene have roles in endometriosis.