Skip to Main Content
  • Become an Access Reviewer
  • Clinical Phenotypes
  • OMMBID Advisory banner
  • Ommbid banner
  • Ommbid latest banner

Abstract

Abstract 

  1. 2-Ketoadipic acid, an intermediate in the metabolism of L-lysine, hydroxy-L-lysine, and L-tryptophan, undergoes successive oxidative decarboxylations by 2-ketoadipic dehydrogenase and glutaryl-CoA dehydrogenase to form glutaryl-CoA and crotonyl-CoA, respectively.

  2. Deficiency of 2-ketoadipic dehydrogenase causes 2-ketoadipic acidemia (MIM 245130), a condition characterized by accumulation and excretion of 2-ketoadipic, 2-aminoadipic, and 2-hydroxyadipic acids, probably without adverse phenotypic effects.

  3. Deficiency of glutaryl-CoA dehydrogenase causes glutaric acidemia type I (MIM 231670), a disorder characterized clinically by dystonia and dyskinesia appearing during the first years of life, chemically by excretion of glutaric and 3-hydroxyglutaric acids in urine, and pathologically by neuronal degeneration of the caudate and putamen. CT and MRI scans often show frontotemporal atrophy and/or arachnoid cysts before the onset of symptoms.

  4. Glutaryl-CoA dehydrogenase deficiency is inherited as an autosomal recessive trait. More than 60 pathogenic mutations have been identified in the GCD gene (19p13.2), and because no one mutation is prominent outside of inbred groups, most GA1 patients are heterozygous for two different mutant alleles. Identification of heterozygous carriers, while possible by demonstration of activity of intermediate enzymes in cultured fibroblasts and peripheral leukocytes, is most accurately done by mutation analysis.

  5. Striatal damage and neurologic phenotype do not develop in all patients, and there is evidence that early supplementation with L-carnitine, vigorous treatment of intercurrent infections with fluids, glucose and insulin, and (perhaps) dietary restriction of lysine and tryptophan can prevent their development in most instances.

  6. Prenatal diagnosis is possible and is based on demonstrating increased concentrations of glutaric acid in amniotic fluid, deficiency of glutaryl-CoA dehydrogenase in cultured amniocytes or (probably) material obtained by CVS, or, in appropriate families, by mutation analysis.

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.