CSF neurotransmitter studies. An infant with ascorbic acid-responsive tyrosinemia.

A female newborn infant with Marfan-like 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 ascrobic acid therapy. These observations suggest that a high level of tyrosine in serum can affect the metabolism in the brain of dopamine and serotonin.