GSTP1 and myeloperoxidase deficiency: In recent years, some of the genetic determinants of MPOD (variants in or near the GSTP1, SCARB1, ABCA1, BCG5, LIPC, ELOVL2, FADS1, FADS2, ALDH3A2, and RPE65 genes) have been identified [70,71,72,73,74], leading Meyers et al. to conclude that “MPOD is a multi-factorial phenotype associated with variation in genes related to carotenoid transport, uptake, and metabolism, independent of known dietary and health influences on MPOD” [71].