title: [Neonatal onset methylmalonic aciduria and homocystinuria:Biochemical and clinical improvement with betaine therapy].
abstract: Methylmalonic aciduria and homocystinuria is a very rare inborn error of cellular cobalamin (Cbl) metabolism. We describe the biochemical evolution and clinical course of a boy with neonatal onset CblC mutant defect.Born after a normal pregnancy, the patient developed general hypotonia and severe feeding difficulties at 5 days of life. Diagnosis of methylmalonic aciduria and homocystinuria was established by amino-acid and organic acid analysis and was confirmed by enzyme and genetic studies. The patient was initially treated with parenteral hydroxocobalamin (1 mg/day), oral carnitine (100 mg/kg/day) and a restricted protein diet. This treatment returned methylmalonic acid levels to normal. Despite the parenteral hydroxocobalamin therapy, the patient showed no improvement in neurological dysfunction, hypotonia or developmental delay. Oral betaine supplementation (3 g/day) from months 3-15 reduced plasma total homocysteine and homocystinuria. The patient showed clinical improvement in neurological and growth development. We conclude that early betaine therapy was safe and effective in our patient with neonatal onset methylmalonic aciduria and homocystinuria type CblC.
authors.affiliation: Servicio de Pediatría, Hospital General de Segovia, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Urbón Artero
authors.forename: J
authors.initials: J
authors.lastname: Aldana Gómez
authors.forename: C
authors.initials: C
authors.lastname: Reig Del Moral
authors.forename: C
authors.initials: C
authors.lastname: Nieto Conde
authors.forename: B
authors.initials: B
authors.lastname: Merinero Cortés
mesh_terms: D000284:Administration, Oral; D000367:Age Factors; D001622:Betaine / Q000008:administration & dosage / Q000627:therapeutic use*; D005765:Gastrointestinal Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D006712:Homocystinuria / Q000175:diagnosis / Q000188:drug therapy* / Q000235:genetics; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008764:Methylmalonic Acid / Q000652:urine*; D013997:Time Factors
chemical_list: D005765:Gastrointestinal Agents; D001622:Betaine; D008764:Methylmalonic Acid
vernacular_title: Aciduria metilmalónica con homocistinuria de inicio neonatal: mejoría bioquímica y clínica con betaína.