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Protein Requirements in Children with Phenylketonuria (PKU)
Author(s) -
Turki Abrar,
Ueda Keiko,
Cheng Barbara,
Giezen Alette,
Stockler Sylvia,
Elango Rajavel
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.742.9
Subject(s) - phenylalanine , christian ministry , leucine , phenylketonurias , medicine , amino acid , pediatrics , endocrinology , chemistry , biochemistry , philosophy , theology
Phenylketonuria (PKU) is an inherited inborn error of phenylalanine (PHE) metabolism caused by deficiency of the hepatic enzyme, phenylalanine hydroxyls (PAH). Therefore PHE accumulates in plasma leading to developmental delay. The major mode of treatment is nutritional management with dietary restriction of PHE and provision of sufficient protein. The dietary protein requirement in children with PKU is unknown, and currently predicted by a factorial calculation.Our objective was to determine the protein requirements in children with PKU using the indicator amino acid oxidation (IAAO) technique. Four PKU children (5‐18y) have been recruited to participate in test protein intakes ranging from deficiency to excess (0.2 – 3.2 g/kg/d) with the IAAO protocol. Each study day, the test protein was provided as 8 hourly meals. With the fifth meal L‐[1‐ 13 C]leucine was provided orally with collection of breath and urine samples.The protein requirement was determined by using a two‐phase linear regression analysis on the change in breath 13 C enrichment, reflecting protein synthesis.The mean protein requirement was determined to be 1.93g/kg/dand is significantly higher than the most recent 2014 recommendations (1.14 – 1.33g/kg/d, based on 120‐140% above current RDA). These initial findings are the first to directly define a quantitative requirement for protein in children with PKU, and indicate that current recommendations may be underestimated. (Supported by Rare Disease Foundation; Ministry of Higher Education in Saudi Arabia and Saudi Arabian Cultural Bureau)