Reduced level of glycine cleavage system in the liver of hyperglycinemia patients.

The activity of the glycine cleavage system in liver of hyperglycinemia with organic acidemia was 1/6 to 1/20 tha of normal human livers. The reduced activity results from the reduction in concentration of the enzyme of the glycine cleavage system. All the protein components of the glycine cleavage system examined were reduced when the activity was determined seprately. H-protein was purified from patients' and control livers, and there was found no difference in their chromatographic properties.