Representative analysis of the rs1800796 (-572C>G) polymorphism. a PCR-RFLP analysis for the -572C>G polymorphism. M DNA size marker; lanes 1, 4, 5, 7 and 8 CC genotype; lanes 2, 3 CG genotype; lane 6 GG genotype. b DNA sequencing analysis for genotypes of the -572C>G polymorphism. The three charts represent the CC, CG and GG genotypes, respectively. The arrows localize the base changes at the nucleotide positions