Association Between Rs3762318 Polymorphism Within The IL23R Gene And Some Clinical Features Of Psoriasis Vulgaris In Chinese Han Population

Background Psoriasis is a common, chronic and papulosquamous skin disease. 90% of all cases are psoriasis vulgaris. Epidemiological data and twin studies have demonstrated that not only environmental factors but also genetic basis might contribute to the development of psoriasis. Multiple susceptibility genes have been reported to be associated with psoriasis on the basis of genetic linkage or association studies. Beyond our first psoriasis genome-wide association studies (GWAS) in Chinese Han population, We found that rs3762318 of IL23R gene showed suggestive association evidence for psoriasis.Objective To study the association between SNP rs3762318 within the IL23R gene and some clinical features of psoriasis vulgaris in Chinese Han population, lay solid foundation for the pathogenesis of psoriasis.Methods Genotype data of SNP rs3762318 were obtained from the previous GWAS including 1,031 cases and 1,117 controls from Illumina Human610-Quad BeadChips and Replication 2 of our follow-up psoriasis study including 1,852 cases and 5,063 controls using Applied Biosystems Taqman genotyping platform.Clinical data were compiled from questionnaires. The appropriate application of social science statistical software package SPSS 10.0 was used for statistical analysis of data.Results 1. The distribution of alleles genotypes and alleles for rs3762318 were significant differences between cases and controls (P=1.92×10^-5, P=2.23×10^-5, respectively). 2. The genotype and allelic frequencies of rs3762318 polymorphism were statistical significance between the pediatric age of onset cases and controls (χ²=25.37,df=2,P=3.09×10^-6;χ²=24.10,df=1,P=9.17×10-7,OR 1.49,95%CI 1.27-1.75). The genotype and allelic frequencies of rs3762318 polymorphism were also statistical significance between the adult age of onset cases and controls (χ²=9.83,df=2,P=7.0×10^-3;χ²=6.75,df=1,P=9.0×10^-3,OR 1.16,95%CI 1.04-1.29). Moreover, there were also statistical significance between the pediatric age of onset and adult age of onset cases (χ²=8.25,df=2,P=0.0016;χ²=7.95,df=1,P=0.005,OR 1.29,95%CI 1.08-1.54). 3. The genotype and allelic frequencies of rs3762318 polymorphism within the IL23R gene were statistical significance between the familial cases and controls (χ²=10.27,df=2,P=6.0×10^-3;χ²=9.68,df=1,P=2×10^-3,OR 1.30,95%CI 1.10-1.53). The genotype and allelic frequencies of rs3762318 polymorphism were also statistical significance between the sporadic cases and controls (χ²=16.13,df=2,P=3.15×10-4;χ²=12.37,df=1,P=4.35×10-4,OR 1.22,95%CI 1.09-1.36). However, there were no statistical significance between the familial and sporadic cases (χ²=0.74,df=2,P=0.693;χ²=0.49,df=1,P=0.49,OR 1.07,95%CI 0.89-1.28). 4. The genotype and allelic frequencies of rs3762318 polymorphism were not statistical significance between the acute guttate cases and controls (χ²=4.80,df=2,P=0.091;χ²=1.27,df=1,P=0.259,OR 1.10,95%CI 0.93-1.30). The genotype and allelic frequencies of rs3762318 polymorphism were statistical significance between the chronic plaque cases and controls (χ²=23.06,df=2,P=9.85×10^-6;χ²=21.18,df=1,P=4.19×10^-6,OR 1.29,95%CI 1.16-1.44). However, there were no statistical significance between the acute guttate and chronic plaque cases (χ²=3.85,df=2,P=0.146;χ²=2.92,df=1,P=0.087,OR 0.85,95%CI 0.71-1.02).Conclusion The results indicate that genetic factor of rs3762318 of IL23R may influence the susceptibility to psoriasis except for acute guttate psoriasis. It is associated with the age of onset but not with family history and lesions type of patients in Chinese Han population.