• Test Code:
    1226
  • Department:
    Molecular Genetics
  • Test Synonyms:
    CFCFTR-Related CBAVDCFTR-Related DisordersCystic fibrosis transmembraneconductance regulator
  • CPT Code(s):
    81222
Background:

Cystic Fibrosis (CF) is the most common autosomal recessive genetic disease in the Caucasian population appearing in approximately one in every 2,500 newborns.  In the Caucasian and Ashkenazi Jewish populations, about one in every 25 individuals carries one copy of a mutation in the CFTR gene at 7q31.2.

Reasons for Referral:

  • Confirmation of clinical diagnosis
  • Carrier identification in persons with a positive or negative family history
  • Reflex testing for newborn screening
  • Testing of Sperm & egg donors
  • Abnormal fetal ultrasound
  • Preconception and carrier screening

Methodology:

Multiplex ligation-dependent probe amplification (MLPA) to detect large CFTR coding region deletions /duplications is performed.  The frequency of large deletions in the CFTR gene is estimated to be 1-3% (Schneider M. et al).

Specimen Requirements:

Blood: Lavender tube (EDTA) or yellow (ACD)

  • Adult: 6.0 mL
  • Child: 6.0 mL
  • Infant: 2.0 mL

Saliva: 2 ORAgene Saliva Kits (OGR-500) used according to manufacturer instructions.  Please contact KDL Client Services for a Saliva Collection Kit for patients that cannot provide a blood sample.

Assisted Saliva: 4 ORAgene Assisted Saliva Kits (OGR-575) used according to manufacturer instructions.  Please contact KDL Client Services for an Assisted Saliva Collection Kit for patients that cannot provide a blood sample.

Skin Fibroblast: Punch Biopsy (cell cultures will be prepared at KDL and used for testing), or 2 T-25 confluent flasks

Prenatal:

  • Direct Amniotic Fluid (10-20mL)
  • Direct CVS
  • Direct POC
  • Cultured Amniocytes (2 T-25 flasks)
  • Cultured CVS (2 T-25 flasks)
  • Cultured Fetal Tissue: Product of Conception (2 T-25 flasks)
  • Cord Blood (1-2mL)

DNA: 5-10µg at a minimum of 60-100ng/µL (DNA must be extracted in a CLIA-certified laboratory or a laboratory meeting equivalent requirements as determined by the CAP and/or CMS)

Notice Regarding Molecular Genetic Testing on CVS or Amniotic Fluid Specimens:

  • Maternal cell rule-out testing will be performed on all prenatal specimens received. Please provide maternal blood in addition to the fetal specimen. Additional charges apply for the maternal cell rule-out test.

For routine testing of blood, saliva and buccal swabs, KDL does NOT accept samples from patients within two (2) weeks of a packed cell/platelet transfusion or within four (4) weeks of a whole blood transfusion.  For extraordinary circumstances, where testing must be performed outside of the above windows, please contact our lab.

A REQUISITION FORM MUST ACCOMPANY ALL SAMPLES.  Please include detailed clinical information, including ethnicity, clinical history, and family history.

Test Performed (Days):

Weekly

Turn Around Time:

14 – 21 Days

Shipment Sensitivity Requirements:

  • Keep specimen cool during transit, but do not ship on dry ice. 
  • Please use the cold pack provided in the KDL shipping kit. 
  • Ship the specimen overnight express, using the FedEx priority overnight label provided. 
  • Contact Client Services at (855) 535-1522 for shipping kits and instructions.

References:

  1. Schneider M. et al, 2007 Clin Genet 72:30-38.

Additional Info:

Related tests, also available in our laboratory:

  • CFTR screen analysis of 60 CFTR variants including all of the variants in the ACMG/ACOG-recommended mutation panel.
  • Full CFTR Sanger sequencing.

Prior to any genetic testing we recommend genetic counseling. To receive forms and information about prenatal diagnostic testing, please contact Client Services at (855) 535-1522.