A case-control association study of APOE promoter region variants with glaucoma in North Indian population

Purpose: Genetic variants in apolipoprotein E (APOE) are reported as risk factors for glaucoma in different ethnic populations, however, there is a scarcity of data from North India. Therefore, the present study aimed to investigate the association of APOE promoter region variants c.-219T > G, c.-427T > C, and c.-491A > T with glaucoma in the North Indian population. Methods: 286 primary glaucoma patients and 300 healthy controls were included in the present study. Promoter region variants (c.-219T > G, c.-427T > C, c.-491A > T) of APOE were genotyped by Sanger sequencing followed by statistical analyses. Results: Present case-control association analysis indicated that the GG genotype of the c.-219T > G variant is more common in glaucoma patients (18.53 %) than in controls (11.33 %) and conferred a 1.9-fold increased risk of glaucoma (OR = 1.92, 95 % CI 1.16-3.16, p = 0.010). This risk is particularly higher in females, showing a 2.7-fold increase (OR = 2.66, 95 % CI 1.10-6.41, p = 0.028). In the recessive model, the GG genotype also exhibited a 1.8-fold increased risk of glaucoma development (OR = 1.78, 95 % CI 1.12-2.83, p = 0.014). During sub-group analysis, GG genotype was more prevalent in POAG group compared to controls, with a 2.3-fold increased risk (OR = 2.27, 95 % CI 1.32-3.89, p = 0.002). However, no significant differences in genotype distribution were found between PACG and PCG vs. controls. Additionally, the genotype and allele frequency distributions for the c.-427T > C and c.-491A > T variants were not statistically significant between cases and controls. Conclusion: Our study shows the association of the c.-219T > G variant in the development of glaucoma in the analyzed Indian population. The present study analyzed the genotype-phenotype correlation between APOE promoter region variants and glaucoma characteristics in the Indian population.