Related Experiment Video
Updated: Jul 30, 2026

One-step Metabolomics: Carbohydrates, Organic and Amino Acids Quantified in a Single Procedure
Published on: June 25, 2010
Phenylketonuria: contemporary screening and diagnosis
1Department of Pediatrics, University of Kentucky, Lexington 40536.
Abstract:
Screening newborns for phenylketonuria (PKU) is a mandatory practice based on measuring a raised blood phenylalanine level. Many factors influence the rate of blood phenylalanine rise so that there are many pitfalls in detecting the 1:10,000 affected infant. About one percent of all babies tested proves to be "false positives." Two-thirds of those with persistent hyperphenylalaninemia prove to have classic PKU. Non-classic PKU with less intense, persistent hyperphenylalaninemia is due to different alterations in the enzyme, phenylalanine hydroxylase. Additionally, about one percent of the confirmed positive patients is due to either a defect in the synthesis or regeneration of the cofactor, tetrahydrobiopterin; these latter forms are not amenable to treatment with the low phenylalanine diet. Screening programs have developed directives regarding the timing and conditions for obtaining the specimens for testing. Specific confirmatory tests of those with positive results must be performed. Even so, about one in 70 affected babies is "missed," resulting in mental retardation, seizures, and neurologic deficits.
Related Concept Videos
Genetic Screens
Forward genetic screens
Forward or “classical” genetic screens involve creating random mutations in an organism’s DNA using radiation, mutagens, or insertion of additional bases, which result in visible changes...
Overview of Protein Metabolism
Amino acids play various roles in the body once they are absorbed into cells. They are restructured...
Inborn Errors of Metabolism
Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase
Nephrotic Syndrome II : Assessment and Medical Management
Type II Diabetes Mellitus III: Clinical Manifestations and Diagnosis

