These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Oral phenylalanine loading test for the diagnosis of dominant guanosine triphosphate cyclohydrolase 1 deficiency.
    Author: López-Laso E, Ormazabal A, Camino R, Gascón FJ, Ochoa JJ, Mateos ME, Muñoz MJ, Pérez-Navero JL, Lao JI, Vilaseca MA, Artuch R.
    Journal: Clin Biochem; 2006 Sep; 39(9):893-7. PubMed ID: 16624273.
    Abstract:
    OBJECTIVES: To evaluate the usefulness of Phe loading test in patients for the diagnosis of guanosine triphosphate cyclohydrolase 1 deficiency (GTPCH). DESIGN AND METHODS: We studied one family composed of 13 members harbouring the Q89X mutation in the GTPCH gene, a non-related pediatric patient with GTPCH deficiency and 8 pediatric controls. 100 mg/kg of L-phenylalanine was orally administered, and blood spot samples were taken at baselines 1, 2, 4 and 6 h post-load. RESULTS: Two out of 7 pediatric patients showed a phenylalanine/tyrosine ratio higher than the previously reported cut-off value of 5.25 at 4 h, while 6 of the 7 adult patients showed a higher value. The only adult patient with a phenylalanine/tyrosine ratio below 5.25 at 4 h was asymptomatic. CONCLUSIONS: A cut-off value of 5.25 seems reliable for interpreting Phe loading test in adult patients with GTPCH deficiency, although a lower value should be established for pediatric patients.
    [Abstract] [Full Text] [Related] [New Search]