CSF Neurotransmitter Studies: An Infant With Ascorbic Acid-Responsive Tyrosinemia

• A female newborn infant with Marfanlike habitus experienced lethargy and hypothermia associated with tyrosinemia that was not corrected by the administration of ascorbic acid at 50 mg/day but that subsequently responded to ascorbic acid at 500 mg/day. Cerebrospinal fluid analysis for neurotransmitter metabolites showed elevated concentrations of homovanillic acid and 5-hydroxyindoleacetic acid when the child was symptomatic and normal concentrations after successful ascorbic acid therapy. These observations suggest that a high level of tyrosine in serum can affect the metabolism in the brain of dopamine and serotonin.(Am J Dis Child 134:492-494, 1980)