In particular, a specific single nucleotide polymorphism (SNP) in the DRD2 gene (C957T, rs6277), has been associated with changes in DRD2 availability and DA neurotransmission (37–39), and T-allele homozygosity has been found highly correlated with BED risk and enhanced DA neurotransmission (34). Here, DRD2 is linked to X-linked cone dysfunction syndrome with myopia.