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

Area of Science:

• Biochemistry
• Neuroscience
• Pediatrics

Background:

• Tyrosinemia, a metabolic disorder, can present with neurological symptoms in newborns.
• Marfan-like habitus may be associated with metabolic conditions.
• Ascorbic acid (vitamin C) plays a role in neurotransmitter synthesis.

Observation:

• A female newborn with Marfan-like habitus presented with lethargy and hypothermia.
• Symptoms were initially unresponsive to a low dose of ascorbic acid (50 mg/day).
• Significant improvement was observed after increasing ascorbic acid dosage to 500 mg/day.

Findings:

• Cerebrospinal fluid analysis revealed elevated homovanillic acid and 5-hydroxyindoleacetic acid during symptomatic periods.
• These neurotransmitter metabolite levels normalized following successful ascorbic acid therapy.
• The findings indicate a potential link between serum tyrosine levels and brain dopamine/serotonin metabolism.

Implications:

• High serum tyrosine concentrations may disrupt central nervous system neurotransmitter synthesis or breakdown.
• This case highlights the importance of considering metabolic disorders in newborns with unexplained symptoms.
• Optimizing ascorbic acid dosage may be crucial for managing certain metabolic derangements in tyrosinemia.