[Study on gene-gene, gene-environmental interactions of DNA repair genes related with age-related cataract]

To investigate the interaction between polymorphisms and environment factors in age related cataract (ARC).

Population-based case-control study. All of 448 cataract cases were selected from cataract eye database and 248 controls were recruited from Funing county. All 18 single nucleotide polymorphism (SNPs) of WRN, OGG1, BLM and ERCC6 genes were genotyped using real-time fluorescent quantitative PCR. The possible risk of ARC was estimated by unconditional Logistic regression. The interaction effects between gene-gene and gene-environment were evaluated by use of multifactor dimensionality reduction (MDR).

Risk of ARC in illiterate group was significantly increased (OR = 1.53, P < 0.05), compared to no illiterate group. The risk of cataract in farmers was significantly high with ORs of 3.75. Long exposure to sunlight may increase cataract risk. Factors such as smoking, drinking, hypertension had no relationship with ARC (P > 0.05). WRN-rs11574311 was still associated with ARC with statistical significance after Bonferroni correction (OR = 1.98, Pa<0.018). There was no evidence for any association at a significance level of P < 0.05 for the remaining alleles. MDR analysis showed a significant interaction model among the six factors: education, solar radiation, WRN-rs11574311, WRN-rs1801195, WRN-rs4733220 and BLM-rs17273206 (consistency inspection accuracy of 0.683 on average, cross validation at 10/10, P = 0.005). Logistic regression model showed that the "high-risk" individuals had a significantly increased risk of ARC, compared to those "low- risk" individual classified by the MDR mode mentioned above(OR = 5.51, P < 0.05).

WRN-rs11574311 allele was the risk factor for ARC, and individuals who carried WRN-rs1801195, WRN-rs4733220 and BLM-rs17273206 allele and low level of education, long sunlight time significantly increased the risk of the ARC.