Carrier screening for expectant individuals and those planning a pregnancy AND diagnostic testing for individuals with symptoms of classic CF.
- Patient Preparation
- Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution).
- Specimen Preparation
- Transport 3 mL whole blood. (Min: 1 mL)
- Storage/Transport Temperature
- Unacceptable Conditions
- Plasma or serum. Specimens collected in sodium heparin or lithium heparin tubes.
- Ambient: 72 hours; Refrigerated: 2 weeks; Frozen: 1 month
Characteristics of Classic Cystic Fibrosis (CF): Chronic sino-pulmonary disease, gastrointestinal malabsorption/pancreatic insufficiency, and obstructive azoospermia. Symptoms of a CFTR-related disorder are often limited to a single organ system such as isolated pancreatitis, bilateral absence of the vas deferens, nasal polyposis, or bronchiectasis.
Incidence: 1 in 2,300 Ashkenazi Jewish, 1 in 2,500 Caucasians, 1 in 13,500 Hispanics, 1 in 15,100 African Americans, 1 in 35,100 Asians.
Inheritance: Autosomal recessive.
Penetrance: High for severe pathogenic variants, variable for moderate and mild pathogenic variants.
Cause of Classic CF: Two severe, or one severe and one moderate, pathogenic CFTR variants on opposite chromosomes.
Cause of CFTR-Related Disorders: Two pathogenic CFTR variants on opposite chromosomes in any of the following combinations: two mild, one mild and one severe or one mild and one moderate.
Pathogenic Variants Tested: See the "Additional Technical Information" document.
Clinical Sensitivity: Ashkenazi Jewish 96 percent; Caucasian 92 percent; Hispanic 80 percent; African American 78 percent; Asian American 55 percent.
Methodology: Polymerase chain reaction (PCR) and fluorescence monitoring.
Analytical Sensitivity & Specificity: 99 percent.
Limitations: Diagnostic errors can occur due to rare sequence variations. Only the 165 pathogenic CFTR variants and 5T variant will be interrogated.
Counseling and informed consent are recommended for genetic testing. Consent forms are available online.
|Component Test Code*||Component Chart Name||LOINC|
|2013675||Cystic Fibrosis, Allele 1||42938-1|
|2013676||Cystic Fibrosis, Allele 2||42939-9|
|2013677||Cystic Fibrosis, 165 Variants, Interp|
|2013692||Cystic Fibrosis 5T Variant||21654-9|
- CF DNA Analysis
- CF Gene Mutation Panel
- CF Molecular Genetic Testing
- CF population carrier screening test
- Classic CF
- Cystic Fibrosis Genotyping