Back to Journals » Pediatric Health, Medicine and Therapeutics » Volume 7

Dietary intervention in the management of phenylketonuria: current perspectives

Authors Rocha JC, MacDonald A

Received 2 August 2016

Accepted for publication 27 September 2016

Published 1 December 2016 Volume 2016:7 Pages 155—163

DOI https://doi.org/10.2147/PHMT.S49329

Checked for plagiarism Yes

Review by Single-blind

Peer reviewers approved by Dr Lucy Goodman

Peer reviewer comments 2

Editor who approved publication: Dr Roosy Aulakh


Júlio César Rocha,1-3 Anita MacDonald4

1Centro de Genética Médica, Centro Hospitalar do Porto – CHP, 2Faculdade de Ciências da Saúde, Universidade Fernando Pessoa, 3Center for Health Technology and Services Research (CINTESIS), Porto, Portugal; 4The Children’s Hospital, Birmingham, UK

Abstract: Phenylketonuria (PKU) is a well-described inborn error of amino acid metabolism that has been treated for >60 years. Enzyme deficiency causes accumulation of phenylalanine (Phe) and if left untreated will lead to profound and irreversible intellectual disability in most children. Traditionally, it has been managed with a low-Phe diet supplemented with a Phe-free protein substitute although newer treatment options mainly in combination with diet are available for some subgroups of patients with PKU, for example, sapropterin, large neutral amino acids, and glycomacropeptide. The diet consists of three parts: 1) severe restriction of dietary Phe; 2) replacement of non-Phe L-amino acids with a protein substitute commonly supplemented with essential fatty acids and other micronutrients; and 3) low-protein foods from fruits, some vegetables, sugars, fats and oil, and special low-protein foods (SLPF). The prescription of diet is challenging for health professionals. The high-carbohydrate diet supplied by a limited range of foods may program food preferences and contribute to obesity in later life. Abnormal tasting and satiety-promoting protein substitutes are administered to coincide with peak appetite times to ensure their consumption, but this practice may impede appetite for other important foods. Intermittent dosing of micronutrients when combined with L-amino acid supplements may lead to their poor bioavailability. Much work is required on the ideal nutritional profiling for special SLPF and Phe-free L-amino acid supplements. Although non-diet treatments are being studied, it is important to continue to fully understand all the consequences of diet therapy as it is likely to remain the foundation of therapy for many years.

Keywords:
phenylalanine, PKU, L-amino acids, sapropterin, glycomacropeptide, large neutral amino acids

Creative Commons License This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.

Download Article [PDF]  View Full Text [HTML][Machine readable]