PEDIATRICS Vol. 31 No. 1 January 1963, pp. 39-46
This Article
Right arrow Full Text (PDF)
Right arrow P3Rs: Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when P3Rs are posted
Right arrow Alert me if a correction is posted
Services
Right arrow E-mail this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Add to My File Cabinet
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by La Du, B. N.
Right arrow Articles by Sober, E. K.
Right arrow Search for Related Content
PubMed
Right arrow Articles by La Du, B. N.
Right arrow Articles by Sober, E. K.

A QUANTITATIVE MICROMETHOD FOR THE DETERMINATION OF PHENYLALANINE AND TYROSINE IN BLOOD AND ITS APPLICATION IN THE DIAGNOSIS OF PHENYLKETONURIA IN INFANTS

Bert N. La Du M.D., Ph.D.1, R. Rodney Howell M.D.1, Patricia J. Michael B.S.1, and Eva K. Sober M.S.1

1 National Institute of Arthritis and Metabolic Diseases, National Institutes of Health, U. S. Public Health Service, Bethesda, Maryland

A simple enzymatic spectrophotometric method has been described which permits the quantitative determination of phenylalanine and tyrosine in 0.10 ml of whole blood. For elevated levels of phenylalanine and tyrosine, the method is rapid, specific, and precise. The method should be of value in establishing the diagnosis of phenylketonuria in infants and in following the blood levels of phenylalanine of those on the low phenylalanine diet.

Analysis of heel-prick samples of premature and term infants has shown that normal infants have a broader range of blood phenylalanine values than adults, and that the levels of tyrosine may be as high as 20 mg/100 ml in older infants and premature babies.

The fact that transient elevation of blood phenylalanine may occur in normal newborn infants must be appreciated in making a diagnosis of phenylketonuria in early infancy.

Submitted on July 19, 1962
Accepted on September 12, 1962




This article has been cited by other articles:


Home page
 ScienceHome page
F. B. Goldstein
Phenylketonuria: Limit in Capacity of Pre-Weanling Rats To Oxidize beta-Phenyllactate and Other agr-Hydroxy Acids
Science, November 19, 1965; 150(3699): 1042 - 1044.
[Abstract] [PDF]