Evaluation of frequency of polymorphism in genes related to estrogen metabolism in infertile women and its correlation with follicular estradiol syntesis

Abstract

Infertility affects 20% of couples of childbearing age. Approximately 30% of the causes of infertility are related to female factors, 30% to male factors, 30% of cases both factors are present and 10% have no apparent cause. About 15% of the causes of female infertility are genetic and include gene mutations and chromosomal aberrations.Hormones are important regulators of fertility. Estradiol is secreted by granulosa cells under the control of hormones such as FSH (follicle stimulating hormone) and LH (luteinizing hormone). The estrogen and FSH act in synergism leading to follicular growth and maturation. It is believed that estradiol exerts a crucial role in the maturation and fertilization oocyte.Follicular fluid (FF) which provides the microenvironment necessary for oocyte development and contain many substances involved in oocyte maturation, fertilization and possibly in the embryo development. Thus, alterations in microenvironment may result in ovulatory dysfunction, poor quality oocyte, reduced fertilization rate, low quality embryos and reduced implantation rates.Genetic polymorphisms in genes involved in the synthesis and metabolism of estradiol such as CYP17A1, CYP19A1, COMT and HSD3B1 and estradiol receptores like ER alpha and beta can modify the action and effect of the hormone in the target tissue.Thus, the objective of this study is to identify the frequency of polymorphisms of ESR1 (PvuII and XbaI) and ESR2 (AluI and RsaI), CYP17A1, CYP19A1, HSD3B1 and COMT in women undergoing assisted reproduction techniques and controls, correlating the data with estradiol synthesis in granulosa cells and peripheral blood and with assisted reproduction outcomes. (AU)