Abstract
Purpose:
To investigate the association of genetic factors with primary open angle glaucoma, as well as high tension and normal tension subphenotypes, in a Chinese Han population.
Methods:
1157 primary open angle glaucoma (POAG) cases, including 860 high-tension glaucoma (HTG) and 297 normal tension glaucoma (NTG), and 934 normal controls were recruited. 13 previously reported associated single nucleotide polymorphisms (SNPs) located at 4 gene regions (rs4656461, rs7555523 at TMCO1; rs1063192, rs523096, rs7049105, rs2157719, rs4977756, rs10116277 at CDKN2B-AS1; rs7916697, rs1900004, rs3858145 at ATOH7; rs33912345, rs10483727 at SIX1/SIX6) were genotyped. Distributions of allele frequencies were compared between cases and controls as well as in the HTG and NTG subgroups. Intra-ocular pressure (IOP), vertical cup disc ratio (VCDR), central corneal thickness (CCT), axial length (AL) and age at diagnosis were also investigated as quantitative phenotypes with genotypes of these SNPs.
Results:
<br /> SNPs rs4656461 (P=0.002, OR=3.18) and rs7555523 (P=0.003, OR=3.31) at TMCO1, rs523096 (5.833x10-5, OR=0.65) and rs2157719 (P=3.528x10-5, OR=0.64) at CDKN2B-AS1, rs33912345 (P=5.503x10-4, OR=0.75) and rs10483727 (P=0.003, OR=0.78) at SIX1/SIX6 were statistically significant associated with POAG. In the subgroup analysis of HTG and NTG, multiple variants in CDKN2B-AS1 and SIX1/SIX6 showed stronger association with NTG than HTG. While SNPs in TMCO1 showed significant association with HTG only. SNPs of rs523096 (P=0.001), rs2157719 (P=0.002) at CDKN2B-AS1 and rs33912345 (P=0.002), rs10483727 (P=0.002) at SIX1/SIX6 were detected association with intraocular pressure (IOP), whose minor alleles associated with increase in IOP.<br />
Conclusions:
Genetic variants in CDKN2B-AS1, SIX1/SIX6 and TMCO1 were associated with POAG in Chinese Han population. Carriers of risk alleles of CDKN2B-AS1 and SIX1/SIX6 seem to be predisposed to POAG developing at lower IOP levels and exhibit stronger association with NTG. Carriers of risk alleles of TMCO1 seem to be predisposed to POAG with high IOP.