ABSTRACT
The disorders of creatine metabolism consist of three abnormalities in the synthesis and transport of creatine. Each disorder is characterized by severely reduced or absent creatine in the central nervous system (CNS) and neurologic manifestations that range from mild developmental delay to severe neurologic disability. Biochemical elucidation of the diagnosis is initiated by analysis of the concentrations of creatine and guanidinoacetate. The syndromes of cerebral creatine deficiency represent an appreciable cohort of inborn errors of metabolism that interfere with CNS function. Most importantly, the syndromes of cerebral creatine deficiency should be considered in any patient with developmental delay. The common biochemical abnormality depletion of creatine in the CNS is likely to be the primary pathogenic mechanism. Treatment with supplemental creatine, a dose of 400 mg/kg per day, was employed and resulted in significant improvement in patients with arginine: glycine amidinotransferase and guanidinoacetatetransferase deficiencies.
