The link between apolipoprotein E, presenilin 1, and kinesin light chain 1 gene polymorphisms and age-related cortical cataracts in the Chinese population

PURPOSE To study whether presenilin 1 (PSEN1), apolipoprotein E (APOE), and kinesin light chain 1 (KLC1) genotypes are associated with the risk of developing age-related cortical cataracts in the Han Chinese population. METHODS We collected and analyzed the blood samples of 227 cortical cataract patients and 263 controls. Genotyping was performed by direct sequencing after PCR amplification, and allele frequencies were tested for the Hardy-Weinberg equilibrium. RESULTS The G allele and GG genotype of KLC1 rs8702 were significantly over-represented among cataract patients, as compared to healthy controls (allele P[χ2]=0.001 and genotype P[χ2]=0.008, respectively) and are associated with an odds ratio for cataract development of 1.54 (95% confidence interval of 1.19-2.01). More specifically, carrying the rs8702 C allele was associated with a decreased cortical cataract risk among individuals devoid of the APOE4 allele (OR=0.55; P[χ2]=0.003), whereas it has no significant effect among APOE4 carriers (OR=0.57; P[χ2]=0.36). CONCLUSIONS The KLC1 and APOE genes may be novel susceptibility genes for age-related cataracts.