The findings and conclusions in this report are those of the author and do not necessarily represent the official position of the Centers for Disease Control and Prevention.
Late-Treated Phenylketonuria and Partial Reversibility of Intellectual Impairment
Article first published online: 4 FEB 2010
© 2010, Copyright the Author(s). Journal Compilation © 2010, Society for Research in Child Development, Inc.
Volume 81, Issue 1, pages 200–211, January/February 2010
How to Cite
Grosse, S. D. (2010), Late-Treated Phenylketonuria and Partial Reversibility of Intellectual Impairment. Child Development, 81: 200–211. doi: 10.1111/j.1467-8624.2009.01389.x
Helpful comments were received from Adele Diamond, Jaime Frias, Michael Glass, Muin Khoury, Loïc de Parscau, John Thompson, Edwin Trevathan, Susan Waisbren, Connie Whitehead, and two anonymous referees. Kumiko Imai and Lijing Ouyang provided translation assistance.
- Issue published online: 4 FEB 2010
- Article first published online: 4 FEB 2010
Individuals with late-treated phenylketonuria (PKU) not detected by newborn screening but who followed dietary treatment for at least 12 months before 7 years of age have intelligence quotient (IQ) scores that range from severe impairment to the low-normal range. Among adults with late-treated PKU in California, 85% of those who were born from 1961 to 1978 had IQ scores of 70 or above. Longitudinal studies with repeated cognitive assessments often show average changes in cognitive test scores as high as 20–45 points. Although the severe cognitive impairment associated with untreated PKU can in many cases be partially reversed with dietary treatment, prompt initiation of treatment following newborn metabolic screening is essential for optimal development and the prevention of disability.