Display Settings:

Format

Send to:

Choose Destination
See comment in PubMed Commons below

CFTR-Related Disorders .

Source

GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2014.
2001 Mar 26 [updated 2008 Feb 19].

Excerpt

DISEASE CHARACTERISTICS:

CFTR-related disorders include cystic fibrosis (CF) and congenital absence of the vas deferens (CAVD). Cystic fibrosis affects epithelia of the respiratory tract, exocrine pancreas, intestine, male genital tract, hepatobiliary system, and exocrine sweat glands, resulting in complex multisystem disease. Pulmonary disease is the major cause of morbidity and mortality in CF. Affected individuals have lower airway inflammation and chronic endobronchial infection, progressing to end-stage lung disease characterized by extensive airway damage (bronchiectasis, cysts, and abscesses) and fibrosis of lung parenchyma. Meconium ileus occurs at birth in 15%-20% of newborns with CF. Pancreatic insufficiency with malabsorption occurs in the great majority of individuals with CF. More than 95% of males with CF are infertile as a result of azoospermia caused by absent, atrophic, or fibrotic Wolffian duct structures. CAVD occurs in men without pulmonary or gastrointestinal manifestations of CF. Affected men have azoospermia and are thus infertile.

DIAGNOSIS/TESTING:

Most commonly the diagnosis of cystic fibrosis (CF) is established in individuals with one or more characteristic phenotypic features of CF plus evidence of an abnormality in cystic fibrosis transmembrane conductance regulator (CFTR) function based on ONE of the following: Presence of two CFTR pathogenic allelic variants

OR. Two abnormal quantitative pilocarpine iontophoresis sweat chloride values (>60 mEq/L) 

OR. Transepithelial nasal potential difference (NPD) measurements characteristic of CF. The CFTR mutation detection rate varies by test method and ethnic background. In some symptomatic individuals, only one or neither disease-causing mutation is detectable; in some carriers, the disease-causing mutation is not detectable. The diagnosis of CFTR-related CAVD is established in males with azoospermia, low volume of ejaculated semen, absence of vas deferens on clinical or ultrasound examination, and at least one disease-causing mutation in CFTR.

MANAGEMENT:

Treatment of manifestations: Treatment/prevention of pulmonary complications using oral, inhaled, or IV antibiotics, bronchodilators, anti-inflammatory agents, mucolytic agents, and chest physiotherapy; lung or heart/lung transplantation in selected patients; topical steroids, antibiotics, and/or surgical intervention for nasal/sinus symptoms; special infant formulas to enhance weight gain; oral pancreatic enzyme replacement with meals in those who are pancreatic insufficient; supplemental feeding, often with an indwelling gastric feeding catheter to increase caloric intake; additional fat-soluble vitamins and zinc; oral ursodiol for biliary sludging/obstruction; management of CF-related diabetes mellitus (CFRD) by an endocrinologist; assisted reproductive technologies (ART) for male infertility. Prevention of secondary complications: Airway clearance using chest physiotherapy (CPT) and a variety of airway clearance techniques (ACTs); antibiotics to eradicate initial airway infection and prevent chronic airway infection; immunizations. Surveillance: Regularly scheduled visits to CF care providers to monitor for subtle changes in physical examination, pulmonary function studies, chest radiographs, specific blood and urine tests; cultures of respiratory tract secretions at least four times yearly in patients who are not yet chronically infected with P. aeruginosa; random serum glucose concentration measured annually to screen for CFRD; assessment of bone density starting in adolescence. Agents/circumstances to avoid: Respiratory irritants (smoke, dust); respiratory infectious agents (especially viruses); dehydration. Evaluation of relatives at risk: Sweat chloride testing of sibs and mothers of affected individuals to determine if they may have mild or not yet symptomatic forms of CF. Therapies under investigation: Antibiotic agents/treatment schedules to delay chronic respiratory tract infection.

GENETIC COUNSELING:

CFTR-related disorders are inherited in an autosomal recessive manner. Sibs of a proband with cystic fibrosis and brothers of a proband with CAVD have a 25% chance of being affected, a 50% chance of being asymptomatic carriers, and a 25% chance of being unaffected and not carriers. Molecular genetic testing for pathogenic allelic variant(s) in CFTR is used for carrier detection in population screening programs. Prenatal testing is possible for pregnancies at increased risk for CFTR-related disorders if the pathogenic variants in the family are known.

Copyright © 1993-2014, University of Washington, Seattle. All rights reserved.

PMID:
20301428
[PubMed]
Books & DocumentsFree full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Write to the Help Desk