title: Hyperinsulinism-hyperammonemia syndrome: a de novo mutation of the GLUD1 gene in twins and a review of the literature.
abstract: Hyperinsulinism-hyperammonemia (HI/HA) syndrome is a rare autosomal dominant disease characterized by recurrent hypoglycemia and persistent mild elevation of plasma ammonia. HI/HA syndrome is one of the more common forms of congenital hyperinsulinism (CHI), caused by activating mutations within the GLUD1 gene that encodes the mitochondrial enzyme glutamate dehydrogenase (GDH). We report here on monozygotic twin girls presented with fasting- and protein-induced hypoglycemia and mild persistent hyperammonemia. Genetic analysis revealed that both girls were heterozygous for a novel missense mutation within exon 11 [c.1499A>T, p.(R443W)] of the GLUD1 gene. Despite early treatment with diazoxide and a low protein diet, they both developed non-hypoglycemic seizures in early childhood followed by cognitive impairment. In addition to their clinical course, a review of the literature on HI/HA syndrome is provided.
authors.forename: Dorotea
authors.identifier: http://orcid.org/0000-0002-4239-519X
authors.initials: D
authors.lastname: Ninković
authors.forename: Vladimir
authors.initials: V
authors.lastname: Sarnavka
authors.forename: Anica
authors.initials: A
authors.lastname: Bašnec
authors.forename: Mario
authors.initials: M
authors.lastname: Ćuk
authors.forename: Danijela Petković
authors.initials: DP
authors.lastname: Ramadža
authors.forename: Ksenija
authors.initials: K
authors.lastname: Fumić
authors.forename: Vesna
authors.initials: V
authors.lastname: Kušec
authors.forename: René
authors.initials: R
authors.lastname: Santer
authors.forename: Ivo
authors.initials: I
authors.lastname: Barić
mesh_terms: D005091:Exons / Q000235:genetics*; D005260:Female; D005969:Glutamate Dehydrogenase / Q000235:genetics*; D006801:Humans; D006946:Hyperinsulinism / Q000235:genetics*; D007003:Hypoglycemia / Q000235:genetics*; D007223:Infant; D020125:Mutation, Missense / Q000235:genetics*; D011379:Prognosis; D014430:Twins, Monozygotic / Q000235:genetics*
chemical_list: D005969:Glutamate Dehydrogenase; C561840:GLUD1 protein, human