Early dietary treated patients with phenylketonuria can achieve normal growth and body composition

Mol Genet Metab. 2013;110 Suppl:S40-3. doi: 10.1016/j.ymgme.2013.10.009. Epub 2013 Oct 22.


Background: In the past, overtreatment may have resulted in growth impairment in patients with phenylketonuria.

Objective: The paper aims to investigate height and body composition in early treated patients with phenylketonuria who were diagnosed between 1981 and 2008.

Design: A cross-sectional study of 89 patients with phenylketonuria and 78 controls aged (mean ± SD, in years) 14.4 ± 6.6 and 15.9 ± 7.1, respectively, was undertaken, including anthropometric and body composition evaluation using bioelectrical impedance. Median Phe concentrations in the last year before study enrollment were used as a measure of metabolic control. Natural protein and amino acid mixture intakes were recorded in patients.

Results: No statistically significant differences were found on height z-scores between patients and controls aged less than 19 years (p=0.301), although all patients with classical phenylketonuria revealed negative height z-scores, resulting in a mean ± SD of -0.65 ± 0.41. Among participants aged 19 years or more, median (p25-p75) of height was significantly higher in controls [168.0 cm (159.2-174.8)] than in patients [160.5 cm (151.9-167.5)] (p=0.017). No significant differences were found between patients and controls regarding fat mass, fat free mass, muscular mass, body cell mass index and phase angle.

Conclusion: Our results suggest that early and continuously treated patients with phenylketonuria born after 1992 can achieve normal growth and body composition, although the negative height z-score in patients with classical phenylketonuria strengthens the continuous need to optimize the quality of their protein intake.

Keywords: Fat free mass; Fat mass; Height; Nutritional status; PAH; PKU; Phase angle; Phe; phenylalanine; phenylalanine hydroxylase; phenylketonuria.

MeSH terms

  • Adolescent
  • Anthropometry
  • Body Composition*
  • Body Height*
  • Case-Control Studies
  • Child
  • Cross-Sectional Studies
  • Electric Impedance
  • Female
  • Humans
  • Male
  • Nutritional Status
  • Phenylalanine / blood*
  • Phenylketonurias / diet therapy*
  • Phenylketonurias / physiopathology*
  • Young Adult


  • Phenylalanine