当前位置： SCI文献检索 > PEDIATRICS期刊下所有文献 > Sweat chloride concentrations in infants homozygous or heterozygous for F508 cystic fibrosis.

Sweat chloride concentrations in infants homozygous or heterozygous for F508 cystic fibrosis.

Abstract：

OBJECTIVE:To determine whether an adequate volume of sweat could be obtained routinely from infants younger than 6 weeks old and to evaluate sweat chloride levels in infants with known genotype statuses, including heterozygote carriers for cystic fibrosis (CF). METHODOLOGY:Infants were evaluated using pilocarpine iontophoresis and measurement of sweat volume and chloride concentration. The majority of these infants were referred because of newborn screening test results positive for CF based on immunoreactive trypsinogen analysis. DNA analyses for the 3-base pair deletion at codon 508 of the CF transmembrane regulator gene (F508 mutation) were performed whenever possible, and patients with CF were categorized by genotype. RESULTS:Sweat tests were performed successfully (>/-50 mg of sweat) in 99.3% of the infants tested, and there was no difference in the proportion of unsuccessful tests in infants younger than or older than 6 weeks of age. The normal mean +/- SD sweat chloride was 10.6 +/- 5.2 mEq/L (95% confidence interval, 9.9-11.3). Patients with CF who are F508 homozygotes or F508 compound heterozygotes or who have two other non-F508 mutant alleles were shown to have similar sweat chloride levels, with mean values of 99.9, 98.8, and 96.6 mEq/L, respectively. The group of infants who were found to be CF (F508) heterozygote carriers, when compared with the healthy group, had mildly but significantly increased sweat chloride concentrations, with a mean +/- SD of 14.9 +/- 8.4 mEq/L (95% confidence interval, 13.4-16.4). CONCLUSIONS:Quantitative pilocarpine iontophoresis can be used successfully in infants younger than 6 weeks of age who are undergoing routine diagnostic evaluations to follow up newborn screening test results that are positive for CF. The upper limit of normal sweat chloride in infants should be revised to 40 mEq/L (mean + 3 SD of the CF heterozygote carrier group). CF heterozygote carrier infants with one F508 mutant allele show phenotypic manifestations of CF, including subclinical elevations of sweat chloride.

journal_name

Pediatrics

journal_title

Pediatrics

authors

Farrell PM,Koscik RE

subject

Has Abstract

pub_date

1996-04-01 00:00:00

pages

524-8

issue

eissn

0031-4005

issn

1098-4275

journal_volume

pub_type

杂志文章

在线工具

Sweat chloride concentrations in infants homozygous or heterozygous for F508 cystic fibrosis.