Growth and body composition in children with classical phenylketonuria: results in 34 patients and review of the literature

J Inherit Metab Dis. 2007 Oct;30(5):694-9. doi: 10.1007/s10545-007-0549-3. Epub 2007 Jul 11.


Treatment of phenylketonuria (PKU, OMIM 261600) means a diet restricted in natural protein and supplemented with phenylalanine (Phe)-free L-amino acid mixtures. Growth impairment has been described even in patients with a total protein intake at or above the recommended dietary allowance (RDA). In the present study, growth and body composition (fat-free mass (FFM) and fat) were recorded over 12 months in 34 treated PKU patients (mean age 8.7 years at baseline). Measurements were compared with those of healthy peers and with general population standard (Z-) scores calculated using the LMS method. In 28 PKU patients, data on birth weight and birth length were available and related to measurements at baseline of the study. Mean total protein intake in PKU patients was 124% (range 77-193%) of the RDA (DACH 2000). No significant differences in growth and body composition were present between PKU patients and healthy populations either at birth or during the study period. The significant correlation of FFM (representing muscle mass) with intake of natural protein--rather than total protein--indicates that the enhancement of tolerance to natural protein may be of value in PKU patients.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Adolescent
  • Amino Acids / administration & dosage*
  • Body Composition*
  • Body Height
  • Body Mass Index
  • Body Weight
  • Case-Control Studies
  • Child
  • Child, Preschool
  • Cross-Sectional Studies
  • Diet, Protein-Restricted / adverse effects*
  • Female
  • Follow-Up Studies
  • Growth Disorders / etiology*
  • Growth Disorders / physiopathology
  • Humans
  • Infant
  • Male
  • Nutrition Policy
  • Phenylketonurias / diet therapy*
  • Phenylketonurias / physiopathology
  • Time Factors
  • Treatment Outcome


  • Amino Acids