Impact of MTHFR gene polymorphism on the outcome of methotrexate treatment in a sample of Iraqi rheumatoid arthritis patients.

Analyze the relationship between genetic variations in the MTHFR gene at SNPs (rs1801131 and rs1801133) and the therapy outcomes for Iraqi patients with rheumatoid arthritis (RA). The study was conducted on a cohort of 95 RA Iraqi patients. Based on their treatment response, the cohort was divided into two groups: the responder (47 patients) and the nonresponder (48 patients), identified after at least three months of methotrexate (MTX) treatment. A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique was employed to analyze the MTHFR variations, specifically at rs1801133 and rs1801131. Overall, rs1801131 followed both codominant and dominate models, in which in the codominant model, GG [OR (95% CI) 0.11 (0.022-0.553)] and TG [OR (95% CI) 0.106 (0.021-0.528)] predict responders compared to the TT genotype; meanwhile, for the dominate model, the presence of both GG and TG genotypes [OR (95% CI) 0.108 (0.023-0.507)] together predict responders compared to the TT genotype. The Ars1801133Grs1801131 haplotype was significantly associated with responders [OR (95% CI): 0.388 (0.208-0.723)], while the Grs1801133Trs1801131 haplotype was associated marginally with nonresponders [OR (95% CI) 1.980 (0.965-4.064)]. In the final multivariate analysis, GG/TGrs1801131 genotypes were independently related to responders after adjustment for patients, disease, and treatment characteristics, while TTrs1801131 genotypes were associated with nonresponders. The Iraqi RA patients showed genetic polymorphism in MTHFR gene rs1801131 with T carrier allele associated with nonresponders to MTX therapy. The rs1801131 followed both codominant and dominant models. The G-carried allele for rs1801131 showed an independent association with responder to MTX therapy after adjustment for patients, disease, and treatment characteristics.

Impact of TYMS gene polymorphism on the outcome of methotrexate treatment in a sample of Iraqi rheumatoid arthritis patients - identification of novel single nucleotide polymorphism: Cross-sectional study.

The current work aims to evaluate the association between genetic mutations in thymidylate synthetase (TYMS gene in exon1 and partial regions of promotor and intron 1 [877 bp, 657,220-658,096 bp]) and the therapeutic outcomes for rheumatoid arthritis (RA) Iraqi patients. An observational cross-sectional study involving 95 RA patients with established RA patients based on their methotrexate treatment responsiveness. Genetic sequencing of the TYMS gene was performed for all patients according to the instruction manuals of the sequencing company (Macrogen Inc. Geumchen, South Korea). Four polymorphisms were identified by sequencing 95 randomly selected patients in the noncoding region of TYMS. Three of these polymorphisms were found in the NCBI database's dbSNP (rs2853741, rs2606241, and rs2853742 SNPs), and one SNP polymorphism is novel (657334). The CTAT (657334, rs2853741, rs2606241, and rs2853742 SNPs) haplotype was significantly associated with responder with odd ratio, 95% confidence interval: 0.506, 0.281-0.912 (P value = .022). In contrast, the other haplotypes were not associated with MTX responsiveness. In the multivariate analysis, after adjusting to the effect of age, sex, smoking, and disease duration, the TCrs2853741 genotype was associated with non-responders (P value = .030). In contrast, the ACrs260641 genotype, after adjusting to the effect of age, sex, and smoking, was associated with non-responders (P value = .035). Genetic polymorphism of the TYMS gene, especially in TCrs2853741 and ACrs260641, predicts non-responder to MTX treatment in RA, while the presence of the CTAT haplotype predicts a good response to MTX treatment.