Cystic Fibrosis (CFTR) 165 Pathogenic Variants with Reflex to Sequencing and Reflex to Deletion/Duplication
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/Multiplex Ligation-dependent Probe Amplification
7-35 days
New York DOH Approval Status
This test is New York DOH approved.
ARUP Consult®
Disease Topics
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. 
Ambient: 72 hours; Refrigerated: 2 weeks; Frozen: 1 month 
Reference Interval
By report
Interpretive Data
Background information for Cystic Fibrosis (CFTR), 165 Pathogenic Variants with Reflex to Sequencing and Reflex to Deletion/Duplication:
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 for 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 and Deletion/Duplication Tests:
97 and 2 percent, respectively.
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.
Methodology for Deletion/Duplication:
Multiplex ligation-dependent probe amplification (MLPA) to detect large CFTR coding region deletions/duplications.
Analytical Sensitivity and Specificity:
99 percent.
Diagnostic errors can occur due to rare sequence variations. The breakpoints of large deletions/duplications will not be determined. Large CFTR inversions and regulatory region and intronic variants will not be detected.

Compliance Statement C: For human genetic inheritable conditions and mutations. This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.

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

If less than two pathogenic variants are identified by the CF 165 Variants assay, then CFTR gene sequencing will be performed. Following sequencing, if less than two pathogenic variants are identified, then CFTR deletion/duplication analysis will be performed. Additional charges will apply for each tier performed.
Hotline History
View Hotline History
CPT Code(s)
81220; if reflexed to Sequencing, add 81223; if reflexed to Del/Dup, add 81222
Component Test Code*Component Chart NameLOINC
2013675Cystic Fibrosis, Allele 142938-1
2013676Cystic Fibrosis, Allele 242939-9
2013682CF 165 Var. w/Rflx to Seq/DD, Interp
2013692Cystic Fibrosis 5T Variant21654-9
* 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 mutation screening, sequencing and deletion/duplication