Cystic Fibrosis DNA Screen

General Information

Lab Name

Lab Code

CFDNA

Epic Name

Cystic Fibrosis DNA Screen

Description

Cystic fibrosis (CF) is an autosomal recessive disease caused by pathogenic variants in the CFTR gene (cystic fibrosis transmembrane conductance regulator). This assay detects over 400 disease-causing variants in CFTR, and includes virtually all pathogenic or likely pathogenic variants present in the CFTR2 Database. (http://cftr2.org and Grody et al. 2001)

CFTR Intron 8 Poly(T) test is reported for individuals with the NM_000492.3:c.350G>A, p.R117H variant AND for evaluating CBAVD.

Indications for Testing Include

Carrier testing in an individual with or without family history of CF, or in the spouse of a CF carrier
Evaluate suspected CF
Establish mutation status of CF-affected individual or obligate carrier
Evaluate male infertility due to Congenital Bilateral Absence of Vas Deferens
Follow up prenatal ultrasound findings that are suspicious for CF
Evaluate idiopathic chronic pancreatitis

References

Committee Opinion No. 691: Carrier Screening for Genetic Conditions. Obstet Gynecol 2017 Mar;129(3):e41-e55.

Deignan JL, et al. CFTR variant testing: a technical standard of the American College of Medical Genetics and Genomics (ACMG). Genet Med 2020 Aug;22(8):1288-1295.

Grody WW, et al. Laboratory standards and guidelines for population-based cystic fibrosis carrier screening. Genet Med 2001, 3:149-54. 11280952

Ong T, Marshall SG, Karczeski BA, et al. Cystic Fibrosis and Congenital Absence of the Vas Deferens. 2001 Mar 26 [Updated 2017 Feb 2]. In: Adam MP, Everman DB, Mirzaa GM, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2022. Available from: https://www.ncbi.nlm.nih.gov/books/NBK1250/

Forms & Requisitions

Genetics Requisition

Synonyms

5T Allele, CBAVD, CF Mutation DNA, CFTR Mutation, Congenital Bilateral Absence of the Vas Deferens, Delta F508, DNA-CF Gene Study, Intron 8, Poly(T)

Components

Code	Name
CFRSLT	Cystic Fibrosis Results
CFCINF	Cystic Fibrosis Clinical Information
CFINT	Cystic Fibrosis Interpretation
CFMET	Cystic Fibrosis Methodology
CFDI	Cystic Fibrosis Director

Interpretation

Guidelines

Genetics and Solid Tumor Diagnostic Testing

Method

Test performed by targeted capture for CFTR followed by next-generation sequencing with Illumina technology. Sequences are aligned to the human genome reference (hg19). This assay sequences all exons and flanking intronic sequences of CFTR to detect single nucleotide variants, and small insertions and deletions. Large insertions and deletions are not detectable by this assay. Reporting is limited to pathogenic and likely pathogenic variants (i.e., variants of uncertain significance will not be reported). CFDNA May 2022-CFDNA reportable variants

This test was developed and its performance characteristics determined by the University of Washington Department of Laboratory Medicine and Pathology. It has not been cleared or approved by the US Food and Drug Administration. This laboratory is certified under the Clinical Laboratory Improvement Amendments (CLIA) as qualified to perform high complexity clinical laboratory testing. This test is used for clinical purposes. It should not be regarded as investigational or for research.

Reference Range

See individual components

Ref. Range Notes

No pathogenic or likely pathogenic variant detected.

Interferences and Limitations

CFDNA is not a full sequencing test. If there is a high index of suspicion for cystic fibrosis, consider ordering full CFTR gene sequencing.

References

Committee Opinion No. 691: Carrier Screening for Genetic Conditions. Obstet Gynecol 2017 Mar;129(3):e41-e55.

Deignan JL, et al. CFTR variant testing: a technical standard of the American College of Medical Genetics and Genomics (ACMG). Genet Med 2020 Aug;22(8):1288-1295.

Grody WW, et al. Laboratory standards and guidelines for population-based cystic fibrosis carrier screening. Genet Med 2001, 3:149-54. 11280952

Ordering & Collection

Specimen Type

Blood, saliva, amniocytes, chorionic villus tissue or cultured cells

Collection

BLOOD:

Adult: 5 mL LAVENDER TOP tube
Child: 2 mL LAVENDER TOP tube
Also acceptable: YELLOW TOP (ACD) tube
Unacceptable: Heparin green top tubes

AMNIOCYTES or CULTURED CHORIONIC VILLUS CELLS:

Two (2) T23 or One (1) T75 flask (minimum 1-T25 flask)

CHORIONIC VILLIS and/or TISSUE:

In sterile tube or culture media, at least 5 mg tissue.

Prenatal testing requires concomitant testing for maternal cell contamination (see Online Test Guide, Lab Mnemonic Maternal Cell Contamination [MCC] for ordering and specimen requirements)

Forms & Requisitions

Genetics Requisition

Handling Instructions

Blood: Refrigerate whole blood up to 1 week.

Amniocytes & cultured CVS cells: hold flasks at room temperature.

Chorionic villi &/or tissue: hold at room temperature

Saliva:
Contact laboratory for validated collection kit.

Outside Laboratories: Ship whole blood at ambient temperature for receipt within 1 week of specimen collection.- For cultured amniocytes or chorionic villus cells and for CVS or other tissue, transport and store at room temperature within 24 hours of obtaining CV or removing cultured cells from incubator.

Quantity

Requested: Entire specimen
Minimum: Blood: 1 mL. Amniocytes, cultured chorionic villus cells, chorionic villi or tissue: as above.

Processing

Receiving Instructions: Processing: Please notify genetics about amniocytes, cultured chorionic villus cells, chorionic villi or tissue.

Note: CF Mutation Analysis is to be done in-house UNLESS approved by Genetics to be sent to a referral lab. If this testing is for diagnosis of Congenital Bilateral Absence of the Vas Deferens (CBAVD), please note this in a comment when logging in the specimen. (The genetics lab will report additional information in these cases.).

Misc Sendout

Performance

Lab Department

Genetics(GEN)

Frequency

Performed weekly. Results within 2 weeks.

Available STAT?

Performing Location(s)

UW-MT	Genetics Attention: Genetics Lab Clinical lab, Room NW220 University of Washington Medical Center 1959 NE Pacific Street Seattle, WA 98195 Tel: 206-598–6429 M–F (7:30 AM–4:00 PM) Fax: 206-616-4584 Lab email: cgateam@uw.edu Tel (EXOME only): 206-543-0459	Faculty Jillian Buchan, PhD, FACMG Runjun Kumar, MD, PhD Regina Kwon, MD, MPH Christina Lockwood, PhD, DABCC, DABMGG Abbye McEwen, MD, PhD Colin Pritchard, MD, PhD Vera Paulson, MD, PhD Eric Konnick, MD, MS He Fang, PhD

Billing & Coding

CPT Codes: 81220
LOINC: 21656-4
Interfaced Order Code: UOW167
Billing Comments: For pricing information, contact Client Support Services 206-520-4600 or 800-713-5198.