The impact of common genetic variants in the mitochondrial glycine cleavage system on relevant metabolites.

The glycine cleavage system (GCS) is a complex of four enzymes enabling glycine to serve as a source of one-carbon units to the cell. We asked whether concentrations of glycine, dimethylglycine, formate, and serine in blood are influenced by variation within GCS genes in a sample of young, healthy individuals. Fifty-two variants tagging (r2 < 0.9) the four GCS genes were tested; one variant, GLDC rs2297442-G, was significantly associated (p = .0007) with decreased glycine concentrations in serum.