Hyperinsulinism-Hypoglycemia-Hyperammonemia Syndrome: A New GLUD1 Mutation

The hyperinsulinism hypoglyemia hyperammonemia syndrome (SHI/HA) is the second most common syndrome of congenital hyperinsulinism. The gain of function mutations of the GLUD-1 gene that encodes for the mitochondrial enzyme glutamate dehydrogenase causes a form of hyperinsulinism associated with hype...

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Autores:
Tipo de recurso:
Fecha de publicación:
2013
Institución:
Universidad del Rosario
Repositorio:
Repositorio EdocUR - U. Rosario
Idioma:
eng
OAI Identifier:
oai:repository.urosario.edu.co:10336/25616
Acceso en línea:
https://doi.org/10.1177/2326409813511871
https://repository.urosario.edu.co/handle/10336/25616
Palabra clave:
Hyperinsulinism
Hypoglycemia
Hyperammonemia
GLUD1 Mutation
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License
http://purl.org/coar/access_right/c_14cb
Description
Summary:The hyperinsulinism hypoglyemia hyperammonemia syndrome (SHI/HA) is the second most common syndrome of congenital hyperinsulinism. The gain of function mutations of the GLUD-1 gene that encodes for the mitochondrial enzyme glutamate dehydrogenase causes a form of hyperinsulinism associated with hyperammonemia. Inheritance of glutamate dehydrogenase (GDH) hyperinsulinism (HI) is autosomal dominant. Patients usually present with recurrent symptomatic hypoglycemia secondary to HI. We present a case report of a 3-year-old girl who presented at 9 months with tonic clonic movements, neurodevelopmental delay, and hypoglycemia (10 mg/dL) not associated with fever or other triggers, requiring high-metabolic flux. Analytical determinations of amino acids, lactic and pyruvic acid, growth hormone, and cortisol were normal, except for HI and hyperammonemia. Genetic studies confirmed a unique genetic variant glutamate dehydrogenase 1 (GLUD1) in the DNA sequence, with unknown significance (heterozygous GLUD1: C 1493>T), serine was replaced by leucine at position GLUD1 AA498 of the protein. Our patient presented adequate response to diazoxide, although there was no hyperammonemia improvement. The role of chronic hyperammonemia in the brain damage is not well known. N-carbamylglutamate (Carbaglu) treatment was used with protein restriction in the diet to lower plasma ammonium with good response. Conclusion: The association of hypoglycemia and hyperammonemia should induce suspicion of SHI/HA, which should be confirmed by molecular studies. The early diagnosis and treatment improves the prognosis.