Association of rheumatoid arthritis according to the degree of genetic homozygosity and gender: Pilot study

Abstract

Rheumatoid arthritis (RA) is a chronic synovial inflammatory autoimmune disease with multifactorial origin. With epigenetic and genetic mechanisms playing a role in the development of RA, the aim of our study was to evaluate the anthropogenetic variability in tested individuals that were diagnosed with rheumatoid arthritis, and the possible influence of gender in expression of illness. 100 patients with rheumatoid arthritis (RA) and 100 healthy control individuals were evaluated. For the estimation of the degree of recessive homozygosity, the homozygously recessive characteristics (HRC) test was performed testing 20 HRCs. There was a significant difference in the individual variations of 20 HRCs between the individuals of the control group and patients with RA (SX2=135.191; p<0.001). The mean values of the tested HRCs significantly differed between individuals of the control group and RA group (MV?SDControl group-5.97?2.02, MV?SDRA group-7.34?2.00, p=<0.001). There was a decrease in variability in the RA group versus the control group (VRA group=27.19%; VControl group=33.79%).There was significant difference in the frequencies of HRCs between those with and without RA in males (p<0.023) and in females (p<0.001). Our findings pointed to the higher degree of recessive homozygosity along with decreased variability in RA patients compared to a healthy control group. Therefore, it may be assumed that different genes in different proportions have certain influence in the processes responsible for RA susceptibility and its different degrees of expression.