Genotype-ocular biometry correlation analysis of eight primary angle closure glaucoma susceptibility loci in a cohort from Northern China.

PURPOSE: Recent genome-wide association studies (GWAS) have verified eight genetic loci that were significantly associated with primary angle-closure glaucoma (PACG). The present study investigated whether these variants are associated with the ocular biometric parameters of anterior chamber depth (ACD) and axial length (AL) in a northern Chinese population, as well as whether there were differences in the association of genetic markers in our cohort based on ethnicity.

METHODS: A case-control association study of 500 patients and 720 controls was undertaken. All individuals were genotyped for eight single nucleotide polymorphisms (SNPs) (rs11024102 in PLEKHA7, rs3753841 in COL11A1, rs1015213 located between PCMTD1 and ST18, rs3816415 in EPDR1, rs1258267 in CHAT, rs736893 in GLIS3, rs7494379 in FERMT2, and rs3739821 mapping between DPM2 and FAM102A) using an improved multiplex ligation detection reaction (iMLDR) technique. Allelic and genotypic frequency differences were evaluated using a logistic regression model. Generalized estimation equation (GEE) analysis was conducted for association testing between genotypes and ocular biometric parameters. False discovery rate (FDR) correction for multiple comparisons was employed, and the statistical power was calculated via power and sample size calculation.

RESULTS: Four of the eight SNPs, rs3753841, rs1258267, rs736893 and rs7494379, were associated with PACG (p = 0.007, 0.0016, 0.0045, 0.045, respectively), and only rs3753841, rs1258267 and rs736893 surpassed the FDR correction. For subgroup analysis, only rs1258267 could withstand multiple testing correction in the Han nationality (p = 0.00571). In the GEE tests, rs3753841, rs1258267 and rs736893 were found to be nominally associated with ACD (p = 0.023, 0.016, 0.01, respectively). However, these associations could not survive FDR correction.

CONCLUSIONS: The SNP rs3753841 in COL11A1, rs1258267 in CHAT and rs736893 in GLIS3 are associated with PACG in northern Chinese people, and the association of genetic markers manifests a tendency of ethnic diversity. Larger population-based studies are warranted to reveal additional PACG loci and ethnic aspects of PACG.