title: [Intellectual development of patients with phenylketonuria; 15-year national screening in The Netherlands].
abstract: OBJECTIVE
  To evaluate the intellectual development of patients with phenylketonuria (PKU) or hyperphenylalaninaemia (HPA).
  
  
  METHODS
  Longitudinal follow-up study.
  
  
  METHODS
  University Children's Hospitals of Amsterdam, Groningen, Nijmegen, and Rotterdam.
  
  
  METHODS
  In September 1974 a nationwide neonatal screening for PKU started in the Netherlands. We obtained data on the intellectual development of 116 patients (101 classical PKU, 15 HPA), all detected and treated in the first 15 years of this screening. The children were tested at 6 ages with different instruments for the assessment of intellectual functions, and the scores were compared with the test norms. Performance and verbal capacities were determined as well as possible sex-related differences.
  
  
  RESULTS
  Our data show that the levels of intellectual functioning of PKU and HPA patients do not differ from test norms until the age of 8 yr 6 months. In the older PKU patients there appears to be a trend towards lower IQ scores. We found no sex differences in the mental functioning of PKU patients.
  
  
  CONCLUSIONS
  Continuation of this study is necessary in order to investigate possible negative effects of PKU on cognitive functioning, especially in the older age groups.
authors.affiliation: Academisch Ziekenhuis Vrije Universiteit, afd. Medische Psychologie, Amsterdam.
authors.forename: J
authors.initials: J
authors.lastname: Huisman
authors.forename: L W
authors.initials: LW
authors.lastname: van der Schot
authors.forename: M M
authors.initials: MM
authors.lastname: Hendrikx
authors.forename: A F
authors.initials: AF
authors.lastname: Kalverboer
authors.forename: F M
authors.initials: FM
authors.lastname: Slijper
mesh_terms: D002648:Child; D002657:Child Development; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007360:Intelligence; D008137:Longitudinal Studies; D008297:Male; D010661:Phenylketonurias / Q000523:psychology*; D012737:Sex Factors; D014888:Wechsler Scales
vernacular_title: De intellectuele ontwikkeling van patiënten met fenylketonurie; 15 jaar landelijke screening in Nederland.