Physical development in patients with phenylketonuria on dietary treatment: A retrospective study

Abstract

ObjectivesTo evaluate the growth and physical development in patients with phenylalanine hydroxylase deficiency who follow exclusively dietary treatment. MethodsAnthropometric measurements of 160 patients with hyperphenylalaninemia who were followed at our center over a 25year period were obtained. Only patients treated exclusively with a protein-restrictive diet supplemented with amino acid mixtures were included. Height, weight and body mass index were measured at birth, at diagnosis, at 6 and 12months of age, and annually until 18years of age in patients with phenylketonuria or until 9years of age in patients with mild hyperphenylalaninemia and compared to official national reference values. The final height of PKU patients was also compared to their expected family height. ResultsThe analysis of z scores suggested no significant differences in physical development between PKU patients and the healthy population during the study period. The final height of PKU patients revealed that they were 2 to 4cm taller than expected when compared to the mean family height (p<0.001). The mean weight and BMI at puberty suggested that many patients with severe PKU, but not other phenotypes, were overweight during this period. ConclusionPhysical development can be optimal in PKU patients regardless of their phenotype and the severity of the diet. A tendency to excessive weight gain is seen in adolescence in the most severe phenotypes.