TPMT and metabolic syndrome: Considering the sample size and the allelic frequency of the four significant associated SNPs: CYP2C19 rs4244285, GABRA2 rs279871, NPY rs16147, TPMT rs1142345, this study has 80% power to detect a mean difference of 0.642, 0.598, 0.612 and 1.132 respectively, in the MetS score variation.