Ordering Recommendation

Carrier screening for expectant individuals and those planning a pregnancy AND diagnostic testing for individuals with symptoms of classic CF.

Mnemonic
CF VAR
Methodology

Polymerase Chain Reaction/Fluorescence Monitoring

Performed

Sun-Sat

Reported

5-14 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
Collect

Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution).

Specimen Preparation

Transport 3 mL whole blood. (Min: 1 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

Plasma or serum. Specimens collected in sodium heparin or lithium heparin tubes.

Remarks
Stability

Ambient: 72 hours; Refrigerated: 2 weeks; Frozen: 1 month

Reference Interval

By report

Interpretive Data

Background information for Cystic Fibrosis (CFTR), 165 Pathogenic Variants:
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.

Compliance Category

Laboratory Developed Test (LDT)

Note

The CF 165-Variants assay includes the 23 pathogenic CF variants recommended by the American College of Medical Genetics for population carrier screening.

Hotline History
N/A
CPT Codes

81220

Components
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
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • CF DNA Analysis
  • CF Gene Mutation Panel
  • CF Molecular Genetic Testing
  • CF population carrier screening test
  • Classic CF
  • Cystic Fibrosis Genotyping
Cystic Fibrosis (CFTR) 165 Pathogenic Variants