title: Reversible lactic acidosis in a newborn with thiamine transporter-2 deficiency.
abstract: Thiamine transporter-2 deficiency is a recessive disease caused by mutations in the SLC19A3 gene. Patients manifest acute episodes of encephalopathy; symmetric lesions in the cortex, basal ganglia, thalami or periaqueductal gray matter, and a dramatic response to biotin or thiamine. We report a 30-day-old patient with mutations in the SLC19A3 gene who presented with acute encephalopathy and increased level of lactate in the blood (8.6 mmol/L) and cerebrospinal fluid (7.12 mmol/L), a high excretion of α-ketoglutarate in the urine, and increased concentrations of the branched-chain amino acids leucine and isoleucine in the plasma. MRI detected bilateral and symmetric cortico-subcortical lesions involving the perirolandic area, bilateral putamina, and medial thalami. Some lesions showed low apparent diffusion coefficient values suggesting an acute evolution; others had high values likely to be subacute or chronic, most likely related to the perinatal period. After treatment with thiamine and biotin, irritability and opisthotonus disappeared, and the patient recovered consciousness. Biochemical disturbances also disappeared within 48 hours. After discontinuing biotin, the patient remained stable for 6 months on thiamine supplementation (20 mg/kg/day). The examination revealed subtle signs of neurologic sequelae, and MRI showed necrotic changes and volume loss in some affected areas. Our observations suggest that patients with thiamine transporter 2 deficiency may be vulnerable to metabolic decompensation during the perinatal period, when energy demands are high. Thiamine defects should be excluded in newborns and infants with lactic acidosis because prognosis largely depends on the time from diagnosis to thiamine supplementation.
authors.affiliation: Department of Child Neurology , Hospital Sant Joan de Déu, Universitat de Barcelona, Barcelona, Spain. bperez@hsjdbcn.org
authors.forename: Belén
authors.initials: B
authors.lastname: Pérez-Dueñas
authors.forename: Mercedes
authors.initials: M
authors.lastname: Serrano
authors.forename: Mónica
authors.initials: M
authors.lastname: Rebollo
authors.forename: Jordi
authors.initials: J
authors.lastname: Muchart
authors.forename: Eva
authors.initials: E
authors.lastname: Gargallo
authors.forename: Celine
authors.initials: C
authors.lastname: Dupuits
authors.forename: Rafael
authors.initials: R
authors.lastname: Artuch
mesh_terms: D000140:Acidosis, Lactic / Q000175:diagnosis* / Q000188:drug therapy; D001710:Biotin / Q000008:administration & dosage; D001774:Blood Chemical Analysis; D002331:Carnitine / Q000008:administration & dosage; D003937:Diagnosis, Differential; D004359:Drug Therapy, Combination; D005500:Follow-Up Studies; D005786:Gene Expression Regulation; D006801:Humans; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D026901:Membrane Transport Proteins / Q000172:deficiency* / Q000235:genetics; D009154:Mutation; D018570:Risk Assessment; D013831:Thiamine / Q000008:administration & dosage; D013832:Thiamine Deficiency / Q000175:diagnosis / Q000188:drug therapy / Q000235:genetics*; D016896:Treatment Outcome; D014899:Wernicke Encephalopathy / Q000175:diagnosis*
chemical_list: D026901:Membrane Transport Proteins; C492291:SLC19A3 protein, human; D001710:Biotin; D002331:Carnitine; D013831:Thiamine
keywords: Leigh syndrome lactic acidosis; SLC19A3 gene; biotin; mitochondrial encephalopathy; perinatal brain injury; thiamine; thiamine transporter-2