Abstract
At the Kennedy Centre for Phenylketonuria, Denmark, large neutral amino acids (LNAAs) are being used to treat adult and adolescent patients who are nonadherent to dietary treatment for phenylketonuria (PKU). At the start of treatment, a patient must undergo dietary analysis and regular blood sampling to measure plasma amino acid (AA) concentrations. The aim of this analysis and treatment is that the patient receives 25–30% of the daily protein requirement from LNAA supplementation and the remaining 70–75% from natural, low-phenylalanine proteins (although some patients have difficulties in maintaining this level of protein intake). Patients are therefore able to follow a more “normal” diet than those adhering to a PKU diet with AA supplementation (in which only 20% of the daily protein requirement is provided from the diet and 80% from AA supplementation). LNAAs have also been used to treat older patients with untreated/late-diagnosed PKU who show profound intellectual, psychological, and behavioral impairments. Treatment with LNAAs has been shown to improve measures of concentration and awareness of external stimuli in some of these patients and thus enhance their socialization, emotionality, frustration tolerance, and mood.
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Abbreviations
- AA:
-
Amino acid
- LNAA:
-
Large neutral amino acid
- OMIM:
-
Online Mendelian Inheritance in Man (database)
- Phe:
-
Phenylalanine
- PKU:
-
Phenylketonuria
- t.i.d:
-
Three times a day
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Acknowledgements
The author takes full responsibility for the content of this article but thanks Caudex Medical (supported by Serono Symposia International Foundation) for their assistance in preparing the initial draft and collating the comments of the author and any other named contributors.
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Communicated by: Nenad Blau
References to electronic database: OMIM
Competing interest: None declared.
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Ahring, K.K. Large neutral amino acids in daily practice. J Inherit Metab Dis 33 (Suppl 3), 187–190 (2010). https://doi.org/10.1007/s10545-010-9069-7
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DOI: https://doi.org/10.1007/s10545-010-9069-7