Ordering Recommendation

For individuals with suspected CF. This test is NOT indicated for routine obstetric carrier screening. If individual is not symptomatic, order Cystic Fibrosis (CFTR) 165 Pathogenic Variants (2013661).




Polymerase Chain Reaction/Fluorescence Monitoring/Sequencing




21-28 days

New York DOH Approval Status

This test is New York DOH approved.

Specimen Required

Patient Preparation

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

Specimen Preparation

Transport 3 mL whole blood. (Min: 2 mL)

Storage/Transport Temperature


Unacceptable Conditions

Plasma or serum. Specimens collected in sodium heparin or lithium heparin tubes. Frozen specimens in glass collection tubes.


Ambient: 72 hours; Refrigerated: 1 week; Frozen: 1 month

Reference Interval

By report

Interpretive Data

Background information for Cystic Fibrosis (CFTR), 165 Pathogenic Variants with Reflex to Sequencing:
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.
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.
Autosomal recessive.
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
: Refer to "Additional Technical Information" document.
Clinical Sensitivity of CF 165-Variants Test:
Ashkenazi Jewish 96 percent; Caucasian 92 percent; Hispanic 80 percent; African American 78 percent; Asian American 55 percent.
Clinical Sensitivity for Sequencing:
97 percent.
Methodology for 165-Variants Test:
Polymerase Chain Reaction (PCR) and fluorescence monitoring.
Methodology for Sequencing:
Bidirectional sequencing of the CFTR coding region and intron-exon boundaries.
Analytical Sensitivity & Specificity:
99 percent.
Diagnostic errors can occur due to rare sequence variations. CFTR promoter and regulatory region variants and large gene deletions/duplications and inversions will not be detected.  

This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the US Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Compliance Category

Laboratory Developed Test (LDT)


If less than two pathogenic variants are identified by the CF 165 Variants assay, then CFTR gene sequencing will be performed. Additional charges apply for each tier performed.

Hotline History


CPT Codes

81220; if reflexed, add 81223


Component Test Code* Component Chart Name LOINC
2013675 Cystic Fibrosis, Allele 1 42938-1
2013676 Cystic Fibrosis, Allele 2 42939-9
2013681 Cystic Fibrosis, 165 Var. w/Rflx, 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.


  • CFTR M
  • CFTR mutation reflex test
Cystic Fibrosis (CFTR) 165 Pathogenic Variants with Reflex to Sequencing