The main focus of treatment for AGAT deficiency is supplementation of creatine, with the goal of replenishing cerebral creatine to normal levels. This is done with oral creatine supplementation. Treatment is most effective if it is started early in life, before symptoms are apparent. Treatment in affected individuals does not reverse intellectual disability or improve cognitive function. For treatment at any age, even if intellectual disability was present, all individuals showed improvement in muscle weakness. In an asymptomatic sibling, who was started on treatment due to the earlier diagnosis of an affected sibling, early intervention with creatine supplementation resulted in improved outcomes when compared to their untreated siblings at the same age. In addition to clinical findings, the effectiveness of treatment can be monitored by following creatine levels in blood and urine as well as the creatine signal by MRS. As creatine is rapidly converted and excreted as creatinine, treatment must be life long to continue to benefit the patient. Treatment during the early years of brain development is most important for preserving brain function.
Arginine:glycine amidinotransferase deficiency
Galactose-1-phosphate uridylyltransferase deficiency
Ornithine aminotransferase deficiency
Ribose-5-phosphate isomerase deficiency
Aminoacylase 1 deficiency
Malonyl-CoA decarboxylase deficiency
Carbamoyl phosphate synthetase I deficiency
Guanidinoacetate methyltransferase deficiency