Psoriasis-associated genetic polymorphism in North Indian population in the CCHCR1 gene and in a genomic segment flanking the HLA-C region

Psoriasis is a common, chronic, recurrent, inflammatory, hyper proliferative disorder of the skin, which has a relatively high prevalence in the general population (0.6-4.8%). Linkage and association analyses in various populations have revealed a major locus for psoriasis susceptibility, PSORS1, at 6p21.3. Association of the disease with human leukocyte antigen (HLA) Cw6, corneodesmosin (CDSN) and the coiled-coil alpha-helical rod protein-1 (CCHCR1) has also been reported. Though the PSORS1 locus accounts for 30-50% of familial psoriasis in various global population groups, yet no studies have been published from the North Indian population. Some of the SNPs in HLA-C and CCHCR1 genes have been reported as markers for disease susceptibility. Therefore in the present study, DNA samples from psoriasis patients from North India were genotyped for polymorphisms in CCHCR1 and HLA-C genes. The allele frequencies were calculated for patients and controls, and were compared for odds ratio and confidence interval values. SNPn.7*22222 (rs12208888), SNPn.7*22333 (rs12216025), SNPn.9*24118 (rs10456057), CCHCR1_386 (rs130065), CCHCR1_404 (rs130076) and CCHCR1_1364 (rs130071) were found to be significant in psoriasis patients. Linkage disequilibrium analysis revealed two haplotypes (rs12208888, rs2844608, rs12216025, rs10456057, rs130065, rs130066, rs130068, rs130269, and rs12208888, rs2844608, rs12216025, rs130076, rs130066, rs130068, rs130269, rs130071) as highly susceptible haplotypes for psoriasis in the cohort studied. Preliminary analysis of the data also suggests the possibilities of ethnic group specific disease related polymorphisms, pending validation in future studies.