title: Executive dysfunction in treated phenylketonuric patients.
abstract: OBJECTIVE
  Executive function deficits have been described in early and continuously treated patients with phenylketonuria (PKU). The aim of this study was to examine performance on executive function tasks of treated patients with PKU diagnosed by 2 years of age.
  
  
  METHODS
  Ten patients with PKU and normal intelligence score who were diagnosed before the age of 2 years and subsequently treated continuously, were compared with 15 typically developing control children on a battery of neuropsychological tests, including the tower of London (TOL), continuous performance test (CPT), and Stroop test.
  
  
  RESULTS
  PKU cases showed significantly poorer performance on the TOL task compared to the control group with the difference being significant in the first three levels of the test. With the CPT, PKU cases had significantly more omission errors than control subjects. On the Stroop test there was no statistically significant difference between the groups. No significant correlation was found between the concurrent serum phenylalanine (Phe) level and results of the executive tests in PKU patients.
  
  
  CONCLUSIONS
  This study identified executive dysfunction in early-treated PKU patients with normal IQ, particularly in the planning and attention domains. Further studies are required to compare the results with those from other neurodevelopmental disorders such as ADHD and autism, to establish whether the pattern of findings is specific to PKU.
authors.affiliation: Child and Adolescent Psychiatry Dept., Institute of Psychiatry, King's College London, London, UK. bahare.azadi@iop.kcl.ac.uk
authors.forename: Bahare
authors.initials: B
authors.lastname: Azadi
authors.forename: Arshia
authors.initials: A
authors.lastname: Seddigh
authors.forename: Mehdi
authors.initials: M
authors.lastname: Tehrani-Doost
authors.forename: Javad
authors.initials: J
authors.lastname: Alaghband-Rad
authors.forename: Mahmoud Reza
authors.initials: MR
authors.lastname: Ashrafi
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology*; D005260:Female; D006801:Humans; D007360:Intelligence; D008297:Male; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D010661:Phenylketonurias / Q000150:complications* / Q000628:therapy; D011340:Problem Solving; D011594:Psychometrics; D011930:Reaction Time; D012016:Reference Values; D012920:Social Behavior Disorders / Q000175:diagnosis* / Q000209:etiology; D055815:Young Adult