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Tryptophan metabolism in phenylketonuria: A French adult cohort study
Author(s) -
Boulet Lysiane,
Besson Gérard,
Van Noolen Laetitia,
Faure Patrice,
Maillot François,
Corne Christelle
Publication year - 2020
Publication title -
journal of inherited metabolic disease
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 102
eISSN - 1573-2665
pISSN - 0141-8955
DOI - 10.1002/jimd.12250
Subject(s) - inborn error of metabolism , kynurenine , phenylalanine , metabolism , medicine , endocrinology , kynurenic acid , population , phenylketonurias , hyperphenylalaninemia , tryptophan , phenylalanine hydroxylase , cohort , amino acid metabolism , chemistry , amino acid , biochemistry , environmental health
Many similarities between tryptophan (Trp) and phenylalanine (Phe) metabolisms exist. It is possible that a modification of Trp metabolism might be seen in phenylketonuria (PKU). As some of these metabolites have neuroactive properties, they should be consider in neurological impairment seen in this pathology and not totally explained by blood Phe concentrations. One hundred and fifty‐one adult PKU patients (mean age 26.8 years) were included for this study. Plasma Trp, kynurenine (KYN), 3‐hydroxykynurenic acid (3HK), and kynurenic acid (KA) were analyzed by liquid chromatography coupled with tandem mass spectrometry. KYN and 3HK were significantly lower in PKU patients compared to general population ( P < .0001), and KA was significantly enhanced is this population ( P = .009). Furthermore, 3HK concentration was significantly different between PKU patients underwent controlled low‐Phe diet compared to PKU patients without this diet ( P = .0016). In PKU patients with diet, taking AA substitute enable higher plasma 3HK concentration than without ( P = .0008) but still not reaching general population level ( P < .0001). Although further study has to be done, it is clear that Trp metabolism is modified in adult PKU patients. An exploration of complete Trp metabolism, and not only Trp concentration, is needed in PKU population, but also in other inborn error of metabolism treated with hypoprotidic diet.