Executive function in school-aged children with phenylketonuria

The hypothesis that, by school age, children with early-treated phenylketonuria (PKU) have specific cognitive deficits in executive function skills was examined in 19 children with PKU and 19 age-, sex-, and IQ-matched control participants. Five tasks were used, three chosen to measure executive, or frontal-lobe, functions (problem-solving, working memory, and verbal fluency) and two as control measures (verbal memory and spatial perception). Children with PKU performed more poorly On the problem-solving task and on the verbal memory task, suggesting that cognitive impairments associated with PKU persist into the school-age years. In addition, cognitive performance among rite children with PKU was found to be specific to the phenylalanine (phe) levels at rite time of testing. The high-phe group performed consistently more poorly than the control group on four of the six measures of the problem-solving task non or? the verbal memory task whereas the low-phe group was comparable to the control group on all measures.