Past Issue

Volume 13, Number 1, Apr-Jun 2019 Pages: 6-11

The Association between TNF-alpha Gene Polymorphisms and Endometriosis in An Iranian Population

Babak Babaabasi, M.Sc., 1, 2, Ali Ahani, Ph.D., 3, *, Faegheh Sadeghi, Ph.D, 4, Haniyeh Bashizade-Fakhar, Ph.D, 5, Hamid Reza Khorram Khorshid, Ph.D, 6,
Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran
Mendel Medical Genetics Laboratory, Tehran, Iran
Department of Molecular Biology, Ahar Branch, Islamic Azad University, Ahar, Iran
Department of Laboratory Science, Chalous Branch, Islamic Azad University, Chalous, Iran
Genetic Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
*Corresponding Address: Mendel Medical Genetics Laboratory Tehran Iran



Tumor necrosis factor-alpha (TNF-α) is an important cytokine in acute inflammatory response to infective factors. Based on investigation in different populations, it is thought that this response increases in patients with endometrio- sis due to the presence of cytokines such as TNF-α. This study aimed to examine the association of four TNF-α polymor- phisms, namely -238G/A, -308G/A, -857C/T and -863C/A, with susceptibility to endometriosis in an Iranian population.

Materials and Methods

We recruited 150 women with endometriosis and 150 women without endometriosis in this case-control study and collected 4 ml of blood from all subjects. After DNA extraction, the polymorphisms were geno- typed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).


The allele frequency of TNF-α -863C/A in the case and control groups showed a significant difference [odds ratios (OR)=0.64, 95% confidence interval (CI)=0.41-0.99, P=0.047] but the result is not significant when Adjust- ing for multiple testing (P=0.188). No significant difference in the allele frequencies of -238G/A (OR=1.07, 95% CI=0.51-2.25, P=0.862), -308G/A (OR=0.79, 95% CI=0.43-1.45, P=0.438) and -857C/T (OR=1.03, 95% CI=0.66- 1.61, P=0.887) was observed. We adjusted all four polymorphism genotypes by age and body mass index (BMI), however, no significant difference was detected. There was an association between the case and control and BMI when adjusting by age (OR=1.082, 95% CI=1.009-1.162, P=0.028).


For the first time the association of the four polymorphisms in the promoter region of the TNF-α gene with endometriosis has been conducted in women of Iranian origin. The present research reveals the -863 A allele may play a role in incidence of endometriosis among Iranian women. Development of endometriosis among those people with -863 A allele seems low. According to the results, the current study indicates that there might be a correlation between BMI and progression of endometriosis.