Genetic Contribution of Tumor Necrosis Factor (TNF)-α Gene Promoter (−1031, −863 and −857) and TNF Receptor 2 Gene Polymorphisms in Endometriosis Susceptibility

Problem: Tumor necrosis factor (TNF)‐α is a major cytokine involved in inflammatory and immune function. The aim of this study was to investigate whether polymorphisms at positions −1031, −863 and −857 in the TNF gene promoter region (TNFA) and TNF receptor type 2 gene (TNFR2) are responsible in part for genetic susceptibility to endometriosis. Methods of study: TNFA and TNFR2 polymorphisms were determined in 123 patients with endometriosis and 165 fertile healthy women by the polymerase chain reaction (PCR) – preferential homoduplex formation assay and PCR‐restriction fragment length polymorphism, respectively. Results: The frequency of the TNFA‐U01 haplotype was increased significantly in patients with endometriosis compared with controls (P = 0.045, OR = 1.45). The TNFA‐U01 haplotype was strongly associated with HLA‐B*0702. No difference was found in TNFR2 polymorphism between patients and controls. Conclusion: Our results indicated that TNFA promoter polymorphism was associated with susceptibility to endometriosis. However, this association was not independent of HLA‐class I polymorphisms.