A genome-wide association study in the Japanese population confirms 9p21 and 14q23 as susceptibility loci for primary open angle glaucoma

Primary open angle glaucoma (POAG) is one of leading causes of adult blindness worldwide. To identify genetic variants associated with susceptibility to POAG, we conducted a genome-wide association study (GWAS) using 1394 cases and 6599 controls. Subsequently, we analyzed 33 single nucleotide polymorphisms (SNPs) which showed suggestive association (P < 1 × 10^-4) by GWAS, using an additional set of 1802 cases and 7212 controls. In addition to confirmation of the association of the chromosome 9p21 locus [rs1063192, P= 5.2 × 10^-11, odds ratio (OR) = 0.75], and 14q23 (rs10483727, P = 9.49 × 10^-8, OR = 0.79) with POAG in Caucasians reported recently, we identified a suggestive-associated locus on 2q21 (rs7588567, P = 3.89 × 10^-7, OR = 0.85). For these described SNPs, minor alleles are suspected to have a protective effect from the disease. An linkage disequilibrium block containing rs10483727 includes the SIX6 gene that was implicated to have a critical role in eye development, and genes in both represented loci (SIX6 on chromosome 14q23, and CDKN2A-CDKN2B on chromosome 9p21) are known to be expressed in human ocular tissues, including the retina. Our GWAS results should contribute to better insight into the genetic basis of POAG.