Creatine deficiency syndrome caused by guanidinoacetate methyltransferase deficiency: Diagnostic tools for a new inborn error of metabolism

摘要: Abstract Hepatic guanidinoacetate methyltransferase deficiency induces a of creatine/phosphocreatine in muscle and brain an accumulation guanidinoacetic acid (GAA), the precursor creatine. We describe patient with this defect, 4-year-old girl dystonic-dyskinetic syndrome addition to developmental delay therapy-resistant epilepsy. Several methods were used diagnosis disease: (1) creatinine excretion 24-hour urine was significantly lowered, whereas concentration plasma randomly collected not strikingly different from control values; (2) Sakaguchi staining reaction guanidino compounds random samples indicated enhanced GAA excretion; (3) measured quantitatively by compound analysis using amino analyzer markedly elevated samples; (4) vivo 1 H magnetic resonance spectroscopy (MRS) revealed strong depletion creatine brain; (5) phosphorus 31 MRS showed decrease phosphocreatine identified as phosphate; (6) vitro 1H absence resonances cerebrospinal fluid occurrence urine. For early detection disease, we recommend patients syndrome, seizures, psychomotor retardation. Positive results should result further investigations including quantitative both MRS. Although epilepsy affected orally administered (400 500 mg/kg per day), treatment resulted clinical improvement increase tissue. (J Pediatr 1997;131:626-31)