title: Glycine and L-arginine treatment causes hyperhomocysteinemia in cerebral creatine transporter deficiency patients.
abstract: Our aim was to monitor folate status in five creatine transporter deficient (CRTR) patients undergoing glycine/L-arginine (Gly/Arg) therapy after the finding of severe hyperhomocysteinemia in one of these cases.Five male patients (age range: 12-20; median = 13 years) genetically confirmed of CRTR deficiency, who were treated with oral glycine (200 mg/kg/day) and L-arginine (400 mg/kg/day) twice a day for 9 months. Clinical follow-up was done at baseline and every 3 months after the start of the therapy. Serum folate was assayed by automated procedures, and plasma total homocysteine (tHcys) by HPLC with fluorescence detection. The 677C→T polymorphism of the methylenetetrahydrofolate reductase (MTHFR) gene was analyzed by PCR.Case 1 presented severe hyperhomocysteinemia (81 μmol/L; control values <10.8) 3 months after Gly/Arg therapy. Three out of the other four cases disclosed mildly increased plasma tHcys values. Serum folate was normal in all cases before therapy, but 3 months after, a deficient status was detected in two cases and a clear decrement in the others when compared with baseline conditions. Two cases were homozygous for the 677C→T polymorphism of the MTHFR, presenting the highest plasma tHcys values. In all cases, after 3 months of folate supplementation (5 mg/day), both serum folate and tHcys concentrations returned to normal values.In conclusion, prior to the start of long-term Gly/Arg therapy, the monitoring of folate and plasma tHcys values, together with study of the 677C→T polymorphism of the MTHFR gene, seems necessary in order to correct hyperhomocysteinemia by means of folate supplementation.
authors: Department of Pediatric Neurology, Hospital Sant Joan de Déu, Passeig Sant Joan de Dèu, 2, Esplugues, Barcelona, 08950, Spain.
authors: Cristina
authors: C
authors: Villar
authors: Jaume
authors: J
authors: Campistol
authors: Carmen
authors: C
authors: Fons
authors: Judith
authors: J
authors: Armstrong
authors: Anna
authors: A
authors: Mas
authors: Aida
authors: A
authors: Ormazabal
authors: Rafael
authors: R
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