The association of TRAP1 gene and TNFSF4 gene polymorphisms with susceptibility of rheumatoid arthritis in a sample of Egyptian patients

Background/aim The disclosure of new gene polymorphisms and their association with rheumatoid arthritis (RA) susceptibility open new windows for better clarification of disease pathogenesis, leading to discovering new therapeutic targets. The present study aimed to explore the association of tumor necrosis factor receptor-associated protein 1 (TRAP1) gene rs8055172 and tumor necrosis factor superfamily number 4 (TNFSF4) gene rs1234315 with susceptibility of RA in a sample of Egyptian patients. Patients and methods This study included 200 RA patients from the Rheumatology Department Outpatients’ Clinic of Kasr El Ainy Teaching Hospital and Centre of Medical Excellence of National Research Centre, Cairo, Egypt. The study also included 200 healthy participants with no family history of autoimmunity serving as a control group. Genotyping of the studied polymorphisms was done using real-time PCR technique. Results The control group showed no significant deviations from Hardy–Weinberg equilibrium regarding rs8055172 and rs1234315 ( P =0.6 and 0.2, respectively). Regarding genotypes of rs8055172, the CC homozygous genotype was more observed among patients. Therefore, the frequency of C allele is higher among RA patients compared with healthy controls ( P =0.001). Logistic regression analysis of rs8055172 genotypes with susceptibility of RA was only significant under the recessive model, where patients carrying CC allele have higher susceptibility to develop RA ( P =0.001, odds ratio=3.1) compared with patients carrying TT and CT allele. On the other hand, distribution of TNFSF4 (rs1234315) genotypes showed no significant difference between controls and RA group ( P =0.7). Conclusions Our results indicate that the TRAP1 gene rs8055172 associates with RA in a population of Egyptians from Cairo, while TNFSF4 gene rs1234315 plays no role in disease susceptibility. A large-scale study to assess the association between TRAP1 gene polymorphism, TRAP1 mRNA expression, and TRAP1 protein level, is needed to clarify the role of TRAP1 gene polymorphism in RA pathogenesis.