DMGDH and hyperinsulinemic hypoglycemia, familial, 4: The method of Coene et al. could not identify guanidinoacetic acid, argininosuccinic acid and dimethylglycine and thus could not recognize guanidinoacetic acid methyltransferase deficiency, argininosuccinic aciduria, and dimethylglycine dehydrogenase deficiency [1].