title: Hyperinsulinism/hyperammonemia (HI/HA) syndrome due to a mutation in the glutamate dehydrogenase gene.
abstract: The hyperinsulinism/hyperammonemia (HI/HA) syndrome is a rare autosomal dominant disease manifested by hypoglycemic symptoms triggered by fasting or high-protein meals, and by elevated serum ammonia. HI/HA is the second most common cause of hyperinsulinemic hypoglycemia of infancy, and it is caused by activating mutations in GLUD1, the gene that encodes mitochondrial enzyme glutamate dehydrogenase (GDH). Biochemical evaluation, as well as direct sequencing of exons and exon-intron boundary regions of the GLUD1 gene, were performed in a 6-year old female patient presenting fasting hypoglycemia and hyperammonemia. The patient was found to be heterozygous for one de novo missense mutation (c.1491A>G; p.Il497Met) previously reported in a Japanese patient. Treatment with diazoxide 100 mg/day promoted complete resolution of the hypoglycemic episodes.
authors.affiliation: Laboratório de Endocrinologia Celular e Molecular, Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brazil. malugia@lim25.fm.usp.br
authors.forename: Maria Lúcia
authors.initials: ML
authors.lastname: Corrêa-Giannella
authors.forename: Daniel Soares
authors.initials: DS
authors.lastname: Freire
authors.forename: Ana Mercedes
authors.initials: AM
authors.lastname: Cavaleiro
authors.forename: Maria Angela Zanella
authors.initials: MA
authors.lastname: Fortes
authors.forename: Ricardo Rodrigues
authors.initials: RR
authors.lastname: Giorgi
authors.forename: Maria Adelaide Albergaria
authors.initials: MA
authors.lastname: Pereira
mesh_terms: D002648:Child; D005260:Female; D005969:Glutamate Dehydrogenase / Q000235:genetics*; D006801:Humans; D006946:Hyperinsulinism / Q000235:genetics*; D007003:Hypoglycemia / Q000235:genetics*; D020125:Mutation, Missense / Q000235:genetics*
chemical_list: D005969:Glutamate Dehydrogenase