Related Experiment Video

Updated: Jun 27, 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

Sweat chloride testing in infants identified as heterozygote carriers by newborn screening

Zafer N Soultan1, Mary M Foster, Nancy B Newman

  • 1Department of Pediatrics, Division of Pediatric Pulmonology, State University of New York, Upstate Medical University, Syracuse, NY, USA.

The Journal of Pediatrics
|November 19, 2008
PubMed

Insights

Newborn screening for cystic fibrosis mutations identified carriers. Reevaluating sweat chloride [C1(-)] reference ranges, a lower borderline of 24 mmol/L is supported to better identify compound heterozygotes.

Area of Science:

  • Biochemistry
  • Genetics
  • Pediatrics

Background:

  • Newborn screening programs identify infants with cystic fibrosis (CF) mutations.
  • Accurate sweat chloride testing is crucial for CF diagnosis.
  • Existing reference ranges may require refinement for carrier identification.

Purpose of the Study:

  • To reevaluate sweat chloride [C1(-)] reference ranges in infants identified as CF mutation carriers.
  • To determine if the current borderline range (30-59 mmol/L) adequately identifies all compound heterozygotes.
  • To propose an optimized borderline range for improved diagnostic accuracy.

Main Methods:

  • Analysis of sweat chloride [C1(-)] levels in 300 infants.
  • Infants were referred due to carrying at least one CF mutation identified via newborn screening.
  • Comparison of diagnostic yield between existing and proposed reference ranges.

Main Results:

  • The existing borderline range of 30 to 59 mmol/L for sweat chloride [C1(-)] was insufficient.
  • This range failed to identify all compound heterozygote individuals.
  • Data suggest a revised borderline range of 24 to 59 mmol/L is more effective.

Conclusions:

  • The current sweat chloride [C1(-)] borderline range needs adjustment.
  • A lower threshold of 24 mmol/L is recommended for the borderline range.
  • This adjustment aims to improve the identification of compound heterozygotes in infants identified through newborn screening.

More Related Videos

Generation of Human Nasal Epithelial Cell Spheroids for Individualized Cystic Fibrosis Transmembrane Conductance Regulator Study08:00

Generation of Human Nasal Epithelial Cell Spheroids for Individualized Cystic Fibrosis Transmembrane Conductance Regulator Study

Published on: April 11, 2018

Rectal Organoid Morphology Analysis (ROMA): A Diagnostic Assay in Cystic Fibrosis07:56

Rectal Organoid Morphology Analysis (ROMA): A Diagnostic Assay in Cystic Fibrosis

Published on: June 10, 2022

Related Concept Videos

Test for Homogeneity01:23

Test for Homogeneity

The goodness–of–fit test can be used to decide whether a population fits a given distribution, but it will not suffice to decide whether two populations follow the same unknown distribution. A different test, called the test for homogeneity, can be used to conclude whether two populations have the same distribution. To calculate the test statistic for a test for homogeneity, follow the same procedure as with the test of independence. The hypotheses for the test for homogeneity can be stated as...
Cystic Fibrosis: Pathogenesis01:23

Cystic Fibrosis: Pathogenesis

Cystic fibrosis (CF), an autosomal recessive disorder, significantly affects the function of exocrine glands. This genetically inherited disease is characterized by the production of thick and sticky mucus, which can severely affect various organs and systems in the body.
CF is primarily caused by a genetic mutation in a chromosome 7 gene coding for the cystic fibrosis transmembrane conductance regulator (CFTR) protein. The most common gene mutation leading to CF is the ΔF508 mutation, but...
Glucose Transporters01:27

Glucose Transporters

Glucose transporters facilitate the transport of glucose across the cell membrane. In addition to glucose, some glucose transporters can also aid the movement of other hexoses such as fructose, mannose, and galactose.
Facilitated diffusion-glucose transporters (GLUTs) are encoded by the solute-linked carrier (SLC) family 2, subfamily A gene family, or SLC2A. The 14 GLUT protein members are distributed into three classes:
Test Cross01:39

Test Cross

Alleles are different forms of the same gene. Humans and other diploid organisms inherit two alleles of every gene, one from each parent.
Punnett Squares01:00

Punnett Squares

Overview
Chi-square Analysis02:46

Chi-square Analysis

The chi-square test is a statistical hypothesis test. It is used to check whether there is a significant difference between an expected value and an observed value. In the context of genetics, it enables us to either accept or reject a hypothesis, based on how much the observed values deviate from the expected values.
The chi-square test was developed by Pearson in 1990.
The first step of performing a Chi-square analysis is to establish a null hypothesis, which assumes that there is no real...