Investigation of Association Between microRNA Variants and Risk of Rheumatoid Arthritis

Abstract

Rheumatoid arthritis (RA) is a chronic autoimmune disorder that affects and damages the joints of human beings. It causes swelling, discomfort, and inflammation in and around the joints and affects other body organs; that affects 1% of the worlds population, with 6 to 60 people out of 100,000 developing the disease each year. However, a recent study describes that there are several factors involved in the regulation of RA disease, including genetic factors like MicroRNAs (miRNAs) variants, which are tiny molecules that bind to complementary target RNA molecules to regulate the protein-coding region of the genome, these non-coding short RNA molecules attach to target mRNA molecules at 3'-untranslated regions (UTR). The current study aimed to investigate the impact of variants rs11614913, rs6505162, and rs3746444 located in MIR196A2, MIR423, and MIR499, respectively, in RA patients. These SNPs were genotyped in RA patients and age- and gender-matched healthy controls using allele-specific T-ARMS-PCR. Allelic and genotypic frequencies of each variant were noted. Furthermore, from the selected variants, the association of rs11614913 and rs6505162 variants with the risk of RA was measured using a statistically odds ratio and confidence of interval (95%). In co-dominant models, the genotypic frequency of MIR423 variant rs6505162 was in cases A/A 75(35.21%), C/C 108 (50.7%) and A/C 30 (14.08%) while in controls A/A 34(16%), C/C 94(44.1%) and A/C 85(40%). These values indicate the best relationship between C/C and A/C, which were higher in cases and found significant association according to P-value and {chi}2. [{chi}2=14.03; P value=0.0009]. This concludes that SNPs (rs6505162) in MIR423 are the susceptibility factors for RA in the Pakistani Population. While SNPs rs11614913 in MIR196A2 have shown no association with RA.