The Effect of BCMO1 Gene Variants on Macular Pigment Optical Density in Young Healthy Caucasians

Background: Serum lutein (L) and zeaxanthin (Z) positively correlate with macular pigment optical density (MPOD); hence, the latter is a valuable indirect tool for measuring L and Z content in the macula. L and Z have been attributed antioxidant capacity and protection from certain retinal diseases but their uptake within the eye is thought to depend on genetic, age, and environmental factors. In particular, gene variants within beta-carotene monooxygenase (BCMO1) are thought to modulate MPOD in the macula. Objectives: To determine the effect of BCMO1 single nucleotide polymorphisms (SNPs) rs11645428, rs6420424, and rs6564851 on MPOD in a cohort of young healthy participants of Caucasian origin with normal ocular health. Design: In this cohort study, MPOD was assessed in 46 healthy participants (22 male and 24 female) with a mean age of 23.8 ± 4.0 years (range 19–33). The three SNPs, rs11645428, rs6420424, rs6564851 that have established associations with MPOD were determined using MassEXTEND (hME) Sequenom assay. One-way analysis of variance was performed on groups segregated into homozygous and heterozygous BCMO1 genotypes. Correlations between body mass index (BMI), iris color, gender, central retinal thickness (CRT), diet, and MPOD were investigated. Results: Macular pigment optical density neither significantly varied with BCMO1 rs11645428 (F(2,41) = 0.70, p = 0.503), rs6420424 (F(2,41) = 0.21, p = 0.801) nor rs6464851 homozygous or heterozygous genotypes (F(2,41) = 0,13, p = 0.88), in this young healthy cohort. The combination of these three SNPs into triple genotypes based on plasma conversion efficiency did not affect MPOD (F(2,41) = 0.07, p = 0.9). There was a significant negative correlation with MPOD and CRT (r = −0.39, p = 0.01) but no significant correlation between BMI, iris color, gender, and MPOD. Conclusion: Our results indicate that macular pigment deposition within the central retina is not dependent on BCMO1 gene variants in young healthy people. We propose that MPOD is saturated in younger persons and/or other gene variant combinations determine its deposition.