Abstract
In a 9 month infant with the spinal fluid (CSF) NT abnormalities of biopterin synthesis defect we compared treatment with:BH4 high (20 mg/kg/d) dose only; BH4 low (3 mg/kg/d), moderate (10 mg/kg/d) or high dose with the NT precursors dopa/carbidopa (10/1 mg/kg/d) and 5-hydroxytryptophan (5 mg/kg/d); and NT precusors with phenylalanine (phe) restricted diet. Over 4 months we evaluated clinical status, CSF biopterin, CSF NT major metabolites homovanilic acid (HVA), 5-hydroxyindolacetic acid (5-HIAA) and 3-methoxy-4-hydroxyphenylglycol, and CSF NT minor metabolites 3,4-dihydroxy-phenylacetic acid, vanilmandelic acid, m-hydroxyphenylacetic acid (MHPAA), p-hydroxyphenylacetic acid (PHPAA) and indolacetic acid (IAA). Few control values for CSF biopterin and NT major metabolites and none for minor metabolites are known in children. Clinically the patient was well on NT precursors with or without BH4 and deteriorated on BH4 only. Liver enzymes, which were elevated at 4 months on BH4 only, remained normal and blood phe was in good control. CSF biopterin increased to at or above normal with moderate or high dose BH4 but virtually no response of HVA or 5-HIAA independent of NT precursors was seen. BH4 at any but low dose altered the IAA/5-HIAA ratio and BH4 at any dose increased PHPAA but not MHPAA. In this patient, the first in which NT minor metabolites have been measured on BH4, the CSF major metabolites could be maintained at normal levels only with NT precursors but BH4 modified the patterns of minor metabolites.
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Greene, C., Cann, H., Milstein, S. et al. TREATMENT OF HYPERPHENYLALANINEMIA V WITH TETRAHYDROBIOPTERIN (BH4) AND NEUROTRANSMITTER (NT) PRECURSORS. Pediatr Res 18 (Suppl 4), 221 (1984). https://doi.org/10.1203/00006450-198404001-00770
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DOI: https://doi.org/10.1203/00006450-198404001-00770