Association of rs182429 variant in TAGAP with rheumatoid arthritis in Pakistani population
Arshad M., Bhatti A., John P., Jalil F., Williams RO.
© 2017 Elsevier B.V. Variations in T-cell activation Rho-GTPase activating protein (TAGAP) have been associated with various autoimmune diseases including Rheumatoid Arthritis (RA). The gene is involved in T cell activation and is therefore of particular interest in context of T cell-driven autoimmune diseases. Genome-wide association studies suggest association between TAGAP and RA in various populations. This study sought to investigate any association of TAGAP with RA in Pakistani population. For this, two variants in TAGAP (rs182429 A/G and rs212389 A/G) were investigated because of their high implication in RA liability of European patients. The variants were genotyped in 186 Pakistani RA patients and 185 controls. No significant difference was observed in distribution of rs212389 between patients and controls (P = 0.87 for genotypic frequency and P = 1.000 for allelic frequency) which differs from findings in European subjects. Conversely, statistically significant difference was observed in rs182429 (P = 0.0026 for genotypic frequency and P = 0.0373 for allelic frequency). Heterozygous genotype AG and allele A were found to be disease susceptible genotype and allele respectively, because of their higher frequency in patients. While higher frequency of genotype GG and allele G in healthy controls suggests them as protective genotype and allele, respectively, in Pakistani population. This is the first TAGAP association study with RA in Pakistani cohort and its results suggest that the distribution of alleles regarding contribution to RA is actually population specific. In future, novel therapeutic targets for RA can be identified by exploring functional significance of these SNPs.