Polymorphisms in ERAP1 gene are associated with psoriasis

Abstract Background Several polymorphisms in ERAP1 gene has been reported to be associated with psoriasis in several different populations. Objective To better understand the association between ERAP1 and psoriasis in Chinese Han population. Methods Seven SNPs (rs27044, rs27043, rs26510, rs469758, rs30378, rs30186 and rs2303208) in ERAP1 gene were genotyped in an independent cohort of 5414 patients and 5556 controls in the Chinese Han population. Results Six SNPs reached the genome wide significance in the combined analysis of exome, targeted sequencing and replication data with the most significant SNP as rs27044 (PRep = 9.92× 10−9, PMeta = 4.05× 10−20). Further haplotype analysis identified 11 haplotypes associated with psoriasis, in which the 2 most significant haplotypes, GCCACT (P = 7.09 × 10−23) and AGTGGC (P = 3.95 × 10−22) were found only in psoriatic cases. Moreover, 2 associated haplotypes were both common in both case and control cohorts, in which ACTGCT showed protective effect (P = 9.64 × 10−10, OR = 0.84) and GGCAGC showed risk effect (P = 1.38 × 10−3, OR = 1.10). Conclusion Our study further reveals the important roles of ERAP1 gene in the pathogenesis of psoriasis, The combination of the haplotypes will be potentially useful in providing information for determining the prediction for the development of psoriasis.