Association of Single-Nucleotide Polymorphisms in ABCC5 Gene with Primary Angle Closure Glaucoma and the Ocular Biometric Parameters in a Northern Chinese Population

Background: The rs1401999 gene in ABCC5 gene was the first locus confirmed by a genome-wide association study (GWAS) to be associated with both anterior chamber depth (ACD) and primary angle closure glaucoma (PACG); however, this locus was of obvious heterogeneity among different populations in the GWAS, and the conclusion has not been further verified by other studies. Therefore, this study was carried out to investigate whether the single-nucleotide polymorphisms (SNPs) in ABCC5 gene are associated with PACG and the ocular biometric parameters ACD and axial length (AL) in samples from northern China. Methods: Case-control association study included 500 PACG patients and 720 unrelated controls from northern China, and genotyping was performed for ten SNPs in ABCC5 gene using an improved multiplex ligation detection reaction technique. The association between these SNPs and risk of PACG was estimated by PLINK using a logistic regression model, while the association between genotypes and ocular biometric parameters was performed by SPSS using generalized estimation equation. Results: An SNP rs4148568 (p = 0.046) and a haplotype TCGGAG (p = 0.0364) in ABCC5 were associated with PACG, and rs4148568 was nominally associated with AL (β = 0.092, p = 0.08). Conclusions: The SNP rs4148568 and a haplotype TCGGAG in ABCC5 contribute to PACG in northern Chinese people. In addition, rs4148568 might be associated with the AL, the variant allele of which may have effect of making the AL longer. Further studies are needed to elucidate the exact mechanism of ABCC5 in the progress of PACG.