On Thu, 20 May 1999, Bob Ferguson wrote:

> Regarding kids w/ PKU, Carlson's Foundations of Physiological
> Psych (p424) says that "Once myelinization is complete, the
> dietary restraints can be relaxed, because a high level of
> phenylalanine no longer no longer threatens brain development."  
> Unfortunately, no references.
> It has been a loooong time since I did any reading on PKU, but in
> the olden days (20 years ago) kids were kept on the
> phenylalanine-free diet into the teenage years.  My memory of the
> literature of the time was that even preteens & teenagers who went
> off the diet were at high risk for irreversible IQ drops snip>
> Can anyone shed any light on this for me?

According to an authoritative source, the March of Dimes website:


"Individuals with PKU must remain on a restricted diet throughout
childhood and adolescence, and perhaps for life. Until the 1980s,
health care providers believed that children with PKU could safely
discontinue their special diet around age 6 when brain growth was
completed. However, high blood levels of phenylalanine in children and
adolescents can lead to a decrease in IQ, to learning disabilities,
and to behavioral disturbances in most-but perhaps not all-children
with PKU. "

"There currently is no good way to predict which individuals with PKU
could discontinue their diets without adverse effects. Parents of
children with PKU and affected adults should discuss their diet and
treatment questions with health care professionals at one of the
special clinics for PKU. "

Looks like Carlson is wrong. In fact, my child psychology text
(Shaffer: Developmental Psychology, 5th ed., 1999 p. 96) says
"Outcomes are best when the affected individuals remain on the special
diet _for life_ [emphasis in the original]. He references M. Verp in
in C. Lin et al (1993), The high-risk fetus, Springer-Verlag.


Stephen Black, Ph.D.                      tel: (819) 822-9600 ext 2470
Department of Psychology                  fax: (819) 822-9661
Bishop's University                    e-mail: [EMAIL PROTECTED]
Lennoxville, QC           
J1M 1Z7                      
Canada     Department web page at http://www.ubishops.ca/ccc/div/soc/psy

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