Takehiko Inui1, Yoichi Wada2, Moriei Shibuya3, Natsuko Arai-Ichinoi4, Yukimune Okubo3, Wakaba Endo3, Toshihiko Uchida5, Noriko Togashi3, Etsuo Naito6, Kazuhiro Haginoya3. 1. Department of Pediatric Neurology, Miyagi Children's Hospital, Miyagi, Japan. Electronic address: inutakejp@yahoo.co.jp. 2. Department of Pediatrics, Tohoku University School of Medicine, Sendai, Japan. 3. Department of Pediatric Neurology, Miyagi Children's Hospital, Miyagi, Japan. 4. Department of Pediatrics, Tohoku University School of Medicine, Sendai, Japan; Department of Pediatrics, Nihon University, Tokyo, Japan. 5. Department of Neonatology, Miyagi Children's Hospital, Miyagi, Japan. 6. Department of Pediatrics, Japanese Red Cross Tokushima Hinomine Rehabilitation Center for People with Disabilities, Tokushima, Japan.
Abstract
BACKGROUND: Pyruvate dehydrogenase complex (PDHC) deficiency is an inborn error of metabolism that causes lactic acidosis and neurodevelopmental changes. Five causative genes have been identified: PDHA1, PDHB, DLAT, DLD, and PDHX. Four neurological phenotypes have been reported: neonatal encephalopathy with lactic acidosis, non-progressive infantile encephalopathy, Leigh syndrome, and relapsing ataxia. Of these, neonatal encephalopathy has the worst mortality and morbidity and there is no effective treatment. SUBJECTS AND METHODS: We studied two girls who were clinically diagnosed with PDHC deficiency as neonates; they were subsequently found to have PDHA1 mutations. The clinical diagnosis was based on white matter loss and a lateral ventricular septum on fetal MRI, spasticity of the lower extremities, and lactic acidosis worsening after birth. Intravenous ketogenic diets were started within 24 h after birth. The ketogenic ratio was increased until the blood lactate level was controlled, while monitoring for side effects. RESULTS: In both cases, the lactic acidosis improved immediately with no apparent side effects. Both children had better developmental outcomes than previously reported cases; neither exhibited epilepsy. CONCLUSIONS: Intravenous ketogenic diet therapy is a treatment option for neonatal-onset PDHC deficiency. Further studies are needed to optimize this therapy.
BACKGROUND: Pyruvate dehydrogenase complex (PDHC) deficiency is an inborn error of metabolism that causes lactic acidosis and neurodevelopmental changes. Five causative genes have been identified: PDHA1, PDHB, DLAT, DLD, and PDHX. Four neurological phenotypes have been reported: neonatal encephalopathy with lactic acidosis, non-progressive infantile encephalopathy, Leigh syndrome, and relapsing ataxia. Of these, neonatal encephalopathy has the worst mortality and morbidity and there is no effective treatment. SUBJECTS AND METHODS: We studied two girls who were clinically diagnosed with PDHC deficiency as neonates; they were subsequently found to have PDHA1 mutations. The clinical diagnosis was based on white matter loss and a lateral ventricular septum on fetal MRI, spasticity of the lower extremities, and lactic acidosis worsening after birth. Intravenous ketogenic diets were started within 24 h after birth. The ketogenic ratio was increased until the blood lactate level was controlled, while monitoring for side effects. RESULTS: In both cases, the lactic acidosis improved immediately with no apparent side effects. Both children had better developmental outcomes than previously reported cases; neither exhibited epilepsy. CONCLUSIONS: Intravenous ketogenic diet therapy is a treatment option for neonatal-onset PDHC deficiency. Further studies are needed to optimize this therapy.