title: Social-cognitive functioning and social skills in patients with early treated phenylketonuria: a PKU-COBESO study.
abstract: Early treatment of phenylketonuria (ET-PKU) prevents mental retardation, but many patients still show cognitive and mood problems. In this study, it was investigated whether ET-PKU-patients have specific phenylalanine (Phe-)related problems with respect to social-cognitive functioning and social skills.
  
  
  
  Ninety five PKU-patients (mean age 21.6 ± 10.2 years) and 95 healthy controls (mean age 19.6 ± 8.7 years) were compared on performance of computerized and paper-and-pencil tasks measuring social-cognitive abilities and on parent- and self-reported social skills, using multivariate analyses of variance, and controlling for general cognitive ability (IQ-estimate). Further comparisons were made between patients using tetrahydrobiopterin (BH4, N = 30) and patients not using BH4. Associations with Phe-levels on the day of testing, during childhood, during adolescence and throughout life were examined.
  
  
  
  PKU-patients showed poorer social-cognitive functioning and reportedly had poorer social skills than controls (regardless of general cognitive abilities). Quality of social-cognitive functioning was negatively related to recent Phe-levels and Phe-levels between 8 and 12 years for adolescents with PKU. Quality of social skills was negatively related to lifetime phenylalanine levels in adult patients, and specifically to Phe-levels between 0 and 7, and between 8 and 12 years. There were no differences with respect to social outcome measures between the BH4 and non-BH4 groups.
  
  
  
  PKU-patients have Phe-related difficulties with social-cognitive functioning and social skills. Problems seem to be more evident among adolescents and adults with PKU. High Phe-levels during childhood and early adolescence seem to be of greater influence than current and recent Phe-levels for these patients.
authors.affiliation: University of Groningen, University Medical Center Groningen, Beatrix Children's Hospital, Division of Metabolic Diseases CA33, PO Box 30.001, 9700 RB, Groningen, The Netherlands. jahjar@umcg.nl.
authors.forename: Rianne
authors.initials: R
authors.lastname: Jahja
authors.affiliation: University of Groningen, University Medical Center Groningen, Beatrix Children's Hospital, Division of Metabolic Diseases CA33, PO Box 30.001, 9700 RB, Groningen, The Netherlands.
authors.forename: Francjan J
authors.initials: FJ
authors.lastname: van Spronsen
authors.affiliation: Department of Clinical Child and Adolescent Studies & Leiden Institute for Brain and Cognition, Leiden University, Leiden, The Netherlands.
authors.forename: Leo M J
authors.initials: LMJ
authors.lastname: de Sonneville
authors.affiliation: Department of Developmental and Clinical Neuropsychology, University of Groningen, Groningen, The Netherlands.
authors.forename: Jaap J
authors.initials: JJ
authors.lastname: van der Meere
authors.affiliation: Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Annet M
authors.initials: AM
authors.lastname: Bosch
authors.affiliation: Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Carla E M
authors.initials: CEM
authors.lastname: Hollak
authors.affiliation: Laboratory Genetics Metabolic Diseases, University Hospital Maastricht, Maastricht, The Netherlands.
authors.forename: M Estela
authors.initials: ME
authors.lastname: Rubio-Gozalbo
authors.affiliation: Laboratory Genetics Metabolic Diseases, University Hospital Maastricht, Maastricht, The Netherlands.
authors.forename: Martijn C G J
authors.initials: MCGJ
authors.lastname: Brouwers
authors.affiliation: Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Floris C
authors.initials: FC
authors.lastname: Hofstede
authors.affiliation: University Medical Center St Radboud Nijmegen, Nijmegen, The Netherlands.
authors.forename: Maaike C
authors.initials: MC
authors.lastname: de Vries
authors.affiliation: University Medical Center St Radboud Nijmegen, Nijmegen, The Netherlands.
authors.forename: Mirian C H
authors.initials: MCH
authors.lastname: Janssen
authors.affiliation: Center for Lysosomal and Metabolic Diseases, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Ans T
authors.initials: AT
authors.lastname: van der Ploeg
authors.affiliation: Center for Lysosomal and Metabolic Diseases, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Janneke G
authors.initials: JG
authors.lastname: Langendonk
authors.affiliation: Department of Clinical Child and Adolescent Studies & Leiden Institute for Brain and Cognition, Leiden University, Leiden, The Netherlands.
authors.forename: Stephan C J
authors.initials: SCJ
authors.lastname: Huijbregts
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003071:Cognition / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D010649:Phenylalanine / Q000378:metabolism; D010661:Phenylketonurias / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology / Q000523:psychology*; D066107:Social Skills; D055815:Young Adult
chemical_list: D010649:Phenylalanine