Test Overview
Test Methodology

The entire CFTR gene is sequenced with Illumina sequencing by synthesis (SBS) chemistry, using the Illumina DNA PCR-Free Tagmentation based whole genome sequencing (WGS) library preparation. Sequences are mapped and aligned to genome reference consortium human build 38 (GRCh38, hg38); variants are called by Illumina DRAGEN germline pipeline and analyzed with the assistance of Illumina Emedgene tertiary analysis pipeline. Average depth of coverage is ≥30x. A minimum sequencing depth of 10x is achieved for all coding regions (+/-15 bp). Regions not meeting these depth metrics are further assessed by either Sanger sequencing or manual review. Pathogenic or likely pathogenic variants, based on the ACMG/AMP guidelines (PMID: 25741868) and ClinGen specifications (clinicalgenome.org/working-groups/sequence-variant-interpretation), and pathogenic or likely pathogenic copy number variants, based on the ACMG/ClinGen standards (PMID: 31690835), are reported. Variants of uncertain clinical significance (VUS) are only reported if specifically requested from the ordering provider following genetic counseling of the screened individual. All reported variants not meeting the quality criteria are confirmed by an orthogonal technology.

Test Usage
 

This pan-ethnic CFTR carrier screening assay utilizes a whole genome sequencing (WGS) platform to sequence the entire CFTR gene. It identifies and reports all pathogenic and likely pathogenic (P/LP) variants. This includes comprehensive coverage of the 100 minimal sequence variants recommended by the American College of Medical Genetics and Genomics (ACMG) in the latest 2023 guidelines, achieving a carrier detection rate of at least 95% across all major US ethnic populations (PMID: 37310422). Furthermore, it expands diagnostic capability by detecting additional CFTR pathogenic sequence variants and copy number variants (CNVs). This assay is intended for reproductive carrier screening in individuals of any ethnic background, with or without a known family history of cystic fibrosis, to precisely define reproductive carrier risk.

Reference Range *

Reference ranges may change over time. Please refer to the original patient report when evaluating results. Interpretive report provided.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Limitations
 

Minimum depth coverage metrics do not apply to regulatory elements or deep intronic regions of the targeted gene; consequently, variants in those regions may not be reliably detected. Balanced structural variants are generally not analyzed. Furthermore, variants outside of the targeted gene are not analyzed. This analysis may not reliably detect mosaicism or CNV in regions with pseudogene interference. Variant classification is based on current scientific knowledge and is subject to change. Test interpretation may be affected by the presence of hematologic malignancies or allogeneic transplants. Because this screen does not detect all pathogenic variants nor report variants without established pathogenicity, a negative result significantly reduces, but does not eliminate, the risk of being a carrier. Reproductive risk is also dependent on the carrier status of the individual’s partner.  

Test Details
Days Set Up
Monday-Friday
Analytic Time

14-28 days

Soft Order Code
CFCAS
MiChart Code
Cystic Fibrosis (CF) Carrier Screening (non-blood)
Synonyms
    Laboratory
    Molecular Genetics Lab
    Reference Laboratory
    MyOme PR51058
    Section
    MMGL Molecular Genetics
    Specimen Requirements
    Collection

    Saliva kit (Oragene OGD-510), follow collection instructions.

    Cheek swab kit (Oracollect OCD-100), follow collection instructions. 

    Collection Instructions
     

    This test is not orderable for MLABS clients.

    Special Handling

    Link to MAGIC form: 

    Alternate Specimen

    Please refer to "Cystic Fibrosis (CF) Carrier Screening" for alternate specimen types.

    Contraindications
    The current literature indicates that genetic tests for an inherited disease should only be conducted once per lifetime.
    Normal Volume

    1 Saliva Kit

    Minimum Volume

    1 Saliva Kit or 2 Cheek Swabs

    Storage Temperature
    Room temperature
    Rejection Criteria
    Specimen at ambient temperature
    Additional Information

    Most insurance carriers require prior authorization for genetic testing. Testing will not begin until insurance prior authorization is received by the laboratory or it is confirmed that prior authorization is not required. The ordering health care provider can obtain the prior authorization or request the laboratory to submit it. To obtain BCN prior authorization call Joint Venture Hospital Laboratories (JVHL) at 800-445-4979; for all other insurances, contact the plan directly. By ordering this test the clinician acknowledges that informed consent, https://mlabs.umich.edu/sites/default/files/2023-04/file/germline-conse…, has been obtained from the patient as required by applicable state or federal laws and the ordering clinician has authorization from the patient permitting MLabs to report the test results to the ordering clinician. Test includes medical geneticist interpretation of results billed as a separate additional charge. This test is not available without interpretation.

    Billing
    CPT Code
    81223
    Pro Fee CPT
    G0452-26
    NY State Approved
    No