Transmembrane Protein 187 (TMEM187) and Interleukin 1 Receptor Associated Kinase (IRAK1) gene polymorphism association with rheumatoid arthritis susceptibility in Egyptian patients.

Rheumatoid arthritis (RA) is a chronic auto-inflammatory disease of connective tissue with progressive joint damage and systemic disorders. RA is considered a multifactorial disease triggered by a genetic predisposition and environmental factors. Polymorphisms have been identified in the Xq28 locus as risk loci for RA. The aim of study was to assess the association between two polymorphisms in the Xq28 region containing Transmembrane Protein 187 (TMEM187) gene (rs13397) and interleukin1 receptor associated kinase (IRAK1) gene (rs1059703) with the disease susceptibility and activity in Egyptian RA patients. This study was conducted on 100 RA patients and 100 age and sex matched normal controls, together were recruited from the Rheumatology Department, Beni-Suef University Hospital. We detected TMEM187 (rs13397) and IRAK1 (rs1059703) gene polymorphisms using the real time PCR TaqMan allelic discrimination assays. We found that the frequency of the major genotypes (GG) of TMEM 187 gene was higher in RA group (54%) compared to controls (50%); while the minor genotypes (AA) was higher in the control group (22%) compared to the diseased one (18%), but such differences did not reach statistical significance (p=0.599). Regarding the IRAK1 gene, we revealed that the frequency of the major genotypes (AA) of the rs1059703 was slightly higher in RA group (48%) compared to controls (46%); while the minor genotypes (GG) was the same in both groups (26%). However, there was higher incidence of minor genotype in the TMEM187 and IRAK1 genes in males; with a statistical significance (p=0.004 and 0.015, respectively). We concluded that the major allele G of TMEM187(rs 13397) could be considered as a risk genetic allele for RA in Egyptian populations.