@article{518ce412aae1493eb55ab80000de2a5e,
title = "Variability in phenylalanine control predicts IQ and executive abilities in children with phenylketonuria",
abstract = "A number of studies have revealed significant relationships between cognitive performance and average phenylalanine (Phe) levels in children with phenylketonuria (PKU), but only a few studies have been conducted to examine the relationships between cognitive performance and variability (fluctuations) in Phe levels. In the current study, we examined a variety of indices of Phe control to determine which index best predicted IQ and executive abilities in 47 school-age children with early- and continuously-treated PKU. Indices of Phe control were mean Phe, the index of dietary control, change in Phe with age, and several indices of variability in Phe (standard deviation, standard error of estimate, and percentage of spikes). These indices were computed over the lifetime and during 3 developmental epochs (<. 5, 5.0-9.9, and ≥. 10. years of age). Results indicated that variability in Phe was generally a stronger predictor of cognitive performance than other indices of Phe control. In addition, executive performance was better predicted by variability in Phe during older than younger developmental epochs. These results indicate that variability in Phe should be carefully controlled to maximize cognitive outcomes and that Phe control should not be liberalized as children with PKU age.",
keywords = "Executive abilities, IQ, Phenylalanine, Phenylketonuria, Variability",
author = "Anna Hood and Grange, {Dorothy K.} and Christ, {Shawn E.} and Robert Steiner and White, {Desir{\'e}e A.}",
note = "Funding Information: The following facts may be considered as potential conflicts of interest. The research detailed in the article was supported by an Investigator Sponsored Trial grant from BioMarin Pharmaceutical Inc. Drs. White, Grange, and Christ serve as consultants to BioMarin Pharmaceutical Inc., and Dr. White serves as a consultant to Merck Serono S.A., but the content of this article has not been influenced by these relationships. Thank you for your attention to our article. Funding Information: This research was supported by a National Institute of Child Health and Human Development grant ( R01HD044901 ), by an Investigator Sponsored Trial grant from BioMarin Pharmaceutical Inc. , and by the Human Clinical Core of the Washington University Intellectual and Developmental Disabilities Research Center which is supported by the National Institute of Child Health and Human Development ( P30HD062171 ) and the James S. McDonnell Foundation . Drs. White, Grange, and Christ have served as consultants to and/or received research funding from BioMarin Pharmaceutical Inc. Dr. White serves as a consultant to Merck Serono S.A. The content of this article has not been influenced by these relationships. The authors wish to thank those who participated in our research for their contributions. We also thank Suzin Blankenship and Laurie Sprietsma for their contributions to study management, as well as the physicians, faculty, and staff of Washington University, Oregon Health & Science University, University of Missouri, New York Medical College, and University of Nebraska who generously contributed to the study through recruitment and phenylalanine monitoring.",
year = "2014",
month = apr,
doi = "10.1016/j.ymgme.2014.01.012",
language = "English",
volume = "111",
pages = "445--451",
journal = "Molecular genetics and metabolism",
issn = "1096-7192",
number = "4",
}