Evaluating of Genetic Polymorphism and Effect of the (HLA-G) Gene on Rheumatoid Arthritis in a Group of Iraqi Patients

Abstract

This study aimed to evaluate the genetic variants of the HLA-G gene and its effect on the severity of rheumatoid arthritis (RA). One hundred samples were collected, including seventy infected people and thirty free of the disease. The patient samples collected starting from December 2022 to February 2023 in Rheumatology department of Baghdad Teaching Hospital. The level of HLA-G was measured in the serum of both infected and healthy people using the ELISA technique, which showed significant differences with statistical significance, where the value of p-value was equal to 0.001 while the value of mean ± SD in healthy people was greater than in patients (84.38 ± 35.99), (45.03 ± 30.03) respectively. The genotypes were determined in the two groups of patients and healthy people using the RT-PCR technique to determine (rs 1063320) SNP for the antigen (HLA-G) and it showed that the genotype (heterozygous) gave the largest value among the other types between patients and healthy people mean ± SD (77.69 ± 53.6) for healthy people and (64.65 ± 95.37) for patients and there were no significant differences as the value was p-value (0.6). In the study of genotypes and allele frequency, the study showed that in Co-dominant the (CG) pattern was the most frequent, as it was in patients (55.7%) while in healthy people (40%) and in Dominant the (CG+GG) pattern was the most frequent (68.6%) in patients and (60%) in healthy people. The Recessive (CC+CG) pattern was also more frequent with a ratio of (87.1%) for patients and (80%) for healthy people. The frequency of the allele (C) was higher than the allele (G) as it was in patients (83%) and healthy people (36%) while the proportions of (57%) and (24%) were for patients and healthy people, respectively. The study showed that the analysis of the balance Hardy-Weinberg Equation showed a balance between the observed values and the expected values. We did not notice any statistically significant differences, as the values of p-values were (0.2) and (0.3) for patients and healthy people, respectively.