Related Experiment Video

Updated: Aug 23, 2026

One-step Metabolomics: Carbohydrates, Organic and Amino Acids Quantified in a Single Procedure
09:28

One-step Metabolomics: Carbohydrates, Organic and Amino Acids Quantified in a Single Procedure

Published on: June 25, 2010

Issues in newborn screening for phenylketonuria

R K Koch1

  • 1University of Southern California School of Medicine, Los Angeles, USA.

American Family Physician
|October 19, 1999
PubMed

Insights

Early newborn screening for phenylketonuria (PKU) prevents intellectual disability. Prompt dietary intervention and repeat testing for infants with developmental delays are crucial for managing PKU effectively.

Area of Science:

  • Medical Genetics
  • Neonatal Screening
  • Metabolic Disorders

Background:

  • Phenylketonuria (PKU) is a genetic disorder that can lead to severe intellectual disability if untreated.
  • Newborn screening programs have significantly reduced the incidence of PKU-related cognitive impairment.
  • Early detection and intervention are critical for managing PKU and preventing its long-term consequences.

Purpose of the Study:

  • To emphasize the importance of timely blood sample collection for newborn screening.
  • To highlight the necessity of repeat testing for positive screening results and infants with developmental delays.
  • To underscore the role of specialized PKU centers and dietary management in preventing sequelae.

Main Methods:

  • Review of established protocols for newborn screening for phenylketonuria.
  • Analysis of the impact of early diagnosis and intervention on patient outcomes.
  • Discussion of the management strategies including dietary restrictions and the role of PKU centers.

Main Results:

  • Newborn screening for PKU, when conducted appropriately, largely prevents mental retardation.
  • Positive phenylalanine test results necessitate a repeat test for confirmation.
  • Delayed development in infants may indicate missed PKU cases, requiring further testing.

Conclusions:

  • Timely blood sampling (at least 12 hours after birth) is essential for accurate newborn screening.
  • Consistent adherence to a phenylalanine-restricted diet, initiated early, is key to preventing PKU sequelae.
  • Ongoing vigilance, including repeat testing and specialized care, is vital for comprehensive PKU management.

More Related Videos

Biochemical Measurement of Neonatal Hypoxia13:13

Biochemical Measurement of Neonatal Hypoxia

Published on: August 24, 2011

Assessment and Evaluation of the High Risk Neonate: The NICU Network Neurobehavioral Scale19:15

Assessment and Evaluation of the High Risk Neonate: The NICU Network Neurobehavioral Scale

Published on: August 25, 2014

Related Concept Videos

Teratogenicity01:07

Teratogenicity

The ability of a drug to produce structural deformations and functional abnormalities in the developing embryo or the fetus is called teratogenicity, and the drug producing this effect is known as a teratogen. Teratogenic effects include stillbirth, miscarriage, intrauterine growth restriction, and neurocognitive delay. A teratogen may affect the embryo at different stages of development, which is important in determining the type and extent of the damage. During blastocyst formation, the early...
Overview of Protein Metabolism01:21

Overview of Protein Metabolism

Proteins are broken down into amino acids during digestion. Unlike fats and carbohydrates, which are stored for later use, proteins are not. Instead, amino acids are either used to produce ATP through oxidation or contribute to the creation of new proteins for the growth and repair of the body. Any surplus amino acids from the diet are converted into glucose or triglycerides rather than excreted.
Amino acids play various roles in the body once they are absorbed into cells. They are restructured...
Pharmacokinetics in Pediatric Patients: Drug Metabolism01:24

Pharmacokinetics in Pediatric Patients: Drug Metabolism

In pediatric care, understanding the nuances of hepatic drug metabolism is crucial, as it significantly differs from that of adults. This divergence is primarily due to the developmental stage of drug-metabolizing enzymes, which affects how medications are processed in the body. In neonates, for instance, the activity of Phase I enzymes—critical for the initial breakdown of drugs—is markedly reduced, functioning at just 20–40% of the levels seen in adults. This reduction poses a challenge in...
Pharmacokinetics in Pediatric Patients: Drug Excretion01:26

Pharmacokinetics in Pediatric Patients: Drug Excretion

In pediatric medicine, understanding the renal function and drug elimination nuances is crucial for administering safe and effective treatments. Newborns, in particular, display markedly slower renal functions than adults, profoundly affecting how drugs are cleared from their bodies. This slower drug clearance requires clinicians to extend the dosing intervals for many medications to prevent drug accumulation and toxicity while ensuring therapeutic efficacy.One key area where these adjustments...
Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes01:28

Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes

Cytochrome P450 (CYP450) enzymes are a superfamily of heme-containing monooxygenases that play a pivotal role in Phase I drug metabolism by catalyzing oxidation and reduction reactions.These enzymes transform lipophilic xenobiotics into more hydrophilic metabolites, facilitating subsequent Phase II conjugation and eventual excretion. The CYP450 family is classified into families (e.g., CYP1–CYP3) and subfamilies (e.g., CYP2A, CYP2C), based on amino acid sequence homology.CYP450 isoenzymes,...
Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase01:27

Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase

Phase II biotransformation reactions are essential for detoxifying and eliminating xenobiotics, including many pharmaceutical compounds. These reactions typically involve conjugation, the covalent attachment of polar endogenous groups such as glucuronic acid, sulfate, methyl, or acetyl moieties to functional groups introduced during Phase I metabolism. The resulting conjugates are more water-soluble, enabling efficient renal or biliary excretion.The major classes of Phase II enzymes include...