Lack of an Association between a Polymorphism in the KRAS 3′ Untranslated Region (rs61764370) and Endometriosis in a Large European Case-Control Study

Abstract

Background: Endometriosis is a common disorder that affects 6–10% of reproductive age women. In a previous study, we demonstrated that a polymorphism in let-7 microRNA-binding site in the 3' untranslated region of the KRAS gene was found in 31% of subjects with endometriosis resistant to medical therapy. This polymorphism was now tested in a large, case-control study. Methods: Peripheral blood or peritoneal biopsies from 2,077 European subjects with or without endometriosis and known infertility were tested for the presence of the variant allele using polymerase chain reaction. Results: Histologically proven endometriosis was found in 1,140 subjects, while 937 subjects were disease free. Variant allele carrier rates in subjects with and without endometriosis were 15.7 and 15.1%, respectively. No association between the variant KRAS allele and stage of the disease, age at surgery, body mass index, or type of infertility was identified. Conclusion: A germ-line single-nucleotide polymorphism in the let-7 microRNA-binding site of the KRAS gene was not associated with sporadic endometriosis in an infertile Caucasian population in this large case-control study. However, it remains possible that this gene variant may be a marker of treatment resistance. Further studies on the role of this polymorphism in endometriosis are needed.