Study On Association Between Polymorphism Of IL23R Gene And Psoriasis Susceptibility In Chinese Han Population

Background Psoriasis is a common inflammatory cutaneous disorder characterized by red scaly patches. The prevalevence of psoriasis is about 0.123% in Chinese Han population. So far, there have been about 4 million psoriasis patients in China. Clinically, psoriasis vulgaris is the most common category in psoriasis, accounting for over 90% of the total number of patients. The exact pathogenesis of psoriasis remains unclear. It is agreed generally that the psoriasis is a complex disease which arises from genetic and environmental factors. The predisposing genes may be grouped into two parts: HLA-associated and non-HLA-associated predisposing genes. During the past ten years, a number of studies have been done by whole-genome scanning method to find the susceptibility genes of psoriasis. To date, 11 psoriasis susceptibility loci have been mapped in Online Mendelian Inheritance in Man (OMIM). In addition, a large number of linkage studies or association analysis studies have been found many predisposing genes of psoriasis in these regions,such as: CCHCR1, HLA-C, HCG27, POU5F1, TCF19, CDSN, LCE3D, LCE3A, IL15 and IL20 and so on.IL23 is a newly discovered immune-mediated inflammatory cytokine, which is a member of the IL12 family, together with IL12 and IL27. It plays an important role in the mechanism of the autoimmune diseases, such as psoriasis, Crohn's disease. IL23 is composed of p19 subunit and p40 subunit, its receptors is formed by IL12Rβ1 and IL23R. IL12B gene codes the p40 subunit and IL23A gene codes the p19 subunit, and two subunits of the IL23 receptor are coded by IL12Rβ1 gene and IL23R gene respectively. Recently, genome-wide association study (GWAS) of the Caucasus from North America and Europe found that: two SNPs (rs11209026 and rs7530511) within IL23R gene were associated with psoriasis susceptibility.Objective To study the relationship between the polymorphism of IL23R gene and psoriasis susceptibility in Chinese Han population.Methods Based on the results of genome wide association study of psoriasis which were performed by our team, we used Sequenom MassArray system to genotype eight tag single nucleotide polymorphisms within IL23R gene and approximately the scope of 10kb upstream and downstream of the gene in 1,103 cases and 1,104 controls, and used the Plink 1.03 software for statistical analysis.Results The differences of allele frequencies of eight TagSNPs between cases and controls were not statistically significant (P>0.05).Conclusions It suggests that polymorphism of IL23R gene might not be related to susceptibility of psoriasis in Chinese Han population.