Developmental Trajectories of Executive and Verbal Processes in Children with Phenylketonuria

ABSTRACT

Phenylketonuria (PKU) is a hereditary disorder characterized by disrupted phenylalanine metabolism and cognitive impairment. However, the precise nature and developmental trajectory of this cognitive impairment remains unclear. The present study used a verbal fluency task to dissociate executive and verbal processes in children with PKU (n = 23; 7–18 years) and controls (n = 44; 7–19 years). Data were collected at three longitudinal timepoints over a three-year period, and the contributions of age, group, and their interaction to fluency performance were evaluated. Results indicated impairments in executive processes in children with PKU, which were exacerbated by declining metabolic control.

Acknowledgments

The authors wish to thank those who participated in our study for their contributions. We also thank Suzin Blankenship, Christen Bass, and Laurie Sprietsma for their contributions to study management, as well as the physicians, faculty, and staff of Washington University and Oregon Health & Science University who generously contributed to recruitment and phenylalanine monitoring.

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Funding

This research was supported by grants from the National Institute of Child Health and Human Development (R01HD044901) and the Intellectual and Developmental Disabilities Research Center at Washington University with funding from the National Institute of Child Health and Human Development (U54HD087011).