title: Intractable absence seizures in hyperinsulinism-hyperammonemia syndrome.
abstract: A girl with intractable absence seizures and facial myoclonia at age 7 years was eventually diagnosed with hyperinsulinism-hyperammonemia syndrome because of hypoglycemia, hyperinsulinism, hyperammonemia, and the results of an oral l-leucine loading test. Her seizures occurred even during periods of relatively normal blood glucose levels, and were completely suppressed by diazoxide treatment only. Her diagnosis of hyperinsulinism-hyperammonemia syndrome was confirmed by a loss of sensitivity of glutamate dehydrogenase for guanosine 5'-triphosphate. Genetic studies identified the I444M mutation in the GLUD1 gene, which encodes glutamate dehydrogenase. This case illustrates the complex relationship between seizures and hypoglycemia in hyperinsulinism-hyperammonemia syndrome that can create diagnostic difficulties. The possibility of hyperinsulinism-hyperammonemia syndrome should be considered in patients with refractory absence seizures with myoclonia.
authors: Department of Pediatrics, Matsuyama Red Cross Hospital, Matsuyama, Japan. knakano@matsuyama.jrc.or.jp
authors: Kousuke
authors: K
authors: Nakano
authors: Katsuhiro
authors: K
authors: Kobayashi
authors: Yoshiyuki
authors: Y
authors: Okano
authors: Kazuyoshi
authors: K
authors: Aso
authors: Yoko
authors: Y
authors: Ohtsuka
mesh_terms: D002648:Child; D004832:Epilepsy, Absence / Q000150:complications* / Q000175:diagnosis* / Q000235:genetics; D005260:Female; D006801:Humans; D006946:Hyperinsulinism / Q000150:complications* / Q000175:diagnosis* / Q000235:genetics; D007003:Hypoglycemia / Q000150:complications* / Q000175:diagnosis* / Q000235:genetics; D009207:Myoclonus / Q000150:complications / Q000175:diagnosis / Q000235:genetics