PPM1K and metabolic syndrome: To understand why obese subjects with MetS who develop IR had lower AT expression of the enzymes involved in BCAA metabolism, we explored whether this finding could be partly associated with the presence of a polymorphism in BCAT2 or BCKDH. We studied two SNPs of BCAT2 and one SNP of BCKDH; these SNPs have a frequency higher of 10 % in HapMap (EMBL-EBI 2013).