Glutaric aciduria is an inherited biochemical disorder caused by a deficiency of the enzyme glutaryl CoA dehydrogenase which is in the mitochondrial biochemical pathway for degradation of the lysine and tryptophane. If not treated, episodes of biochemical intoxication cause degeneration of the basal ganglia of the brain and progressive paralysis. Children who have glutaric aciduria and have suffered significant brain damage often mistakenly are given a diagnosis cerebral palsy. When first seen during an acute illnesses children are commonly thought to have tonic seizures, encephalitis, or Reye syndrome. Early signs of an acute metabolic illness include irritability, loss of appetite, vomiting, lethargy, and hypotonia, however, after the onset of illness brain injury may evolve rapidly.
Patients can become stuporous or comatose within a few hours after signs of illness are first seen.
Intoxication of the brain develops prior to obvious disturbances of blood chemistries. Hypoglycemia, moderate to severe metabolic acidosis, and hyperammonemia develop late in the course of illness, are signs of severe metabolic decompensation, and should be considered medical emergencies. Pathological metabolites are probably generated within the basal ganglia itself. Brain intoxication typically occurs in the absence of hypoglycemia or acidemia. I have managed, and others have reported, patients who have had severe brain intoxication without marked increases in glutaric acid concentrations in the blood or urine.