Danger of high-protein dietary supplements to persons with hyperphenylalaninaemia

R. Koch, K. D. Moseley, R. Moats, S. Yano, R. Matalon, F. Guttler

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


A 16-year-old adolescent with mild hyperphenylalaninaemia was given a high-protein 'body building' supplement twice daily, causing headaches, decreased school performance and mild depression. All symptoms disappeared after cessation of the supplement. The phenylalanine hydroxylase mutation H170D/IVS1nt5G>T was found to be responsive to tetrahydrobiopterin with significant decrease in blood phenylalanine concentration and increase in tyrosine blood content. A brain phenylalanine level of 0.5 mmol/L was initially documented, which decreased to the normal carrier range of 0.2 mmol/L within one month of discontinuance of the protein supplement. At present, the patient is on a normal diet without phenylalanine restriction.

Original languageEnglish (US)
Pages (from-to)339-342
Number of pages4
JournalJournal of Inherited Metabolic Disease
Issue number4
StatePublished - 2003

ASJC Scopus subject areas

  • Genetics
  • Genetics(clinical)


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