Cystic Fibrosis Pathogenic Variant Analysis.




Test Mnemonic

CFMDX

CPT Codes

  • 81220 - QTY (1)

Performing Laboratory

Cleveland Clinic Laboratories


Specimen Requirements

Volume Type Container Collect Temperature Transport Temperature Special Instructions
4 mLWhole bloodEDTA (Lavender)AmbientAmbientBlood specimens are transported and stored at room temperature no longer than 48 hours

Stability

Environmental Condition Description
AmbientBlood may be transported ambient temperature within 48 hours.
RefrigeratedBlood may be transported ambient temperature within 48 hours. After 48 hours blood must be stored at 2-8 degree C for up to 7 days.
FrozenFrozen samples will be rejected.

Days Performed

1 day per week

Turnaround Time

10 days

Methodology

Name Description
Polymerase Chain Reaction (PCR) 
Single Nucleotide Extension (SNE) 
Matrix-assisted Laser Desorption Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry  

Special Info

This test may not be appropriate for follow-up testing of the partners of known carriers. Genetics consultation may be of benefit in determining the appropriate testing strategy in these circumstances.

Clinical Info

The test is intended for cystic fibrosis carrier screening in adults of reproductive age, in confirmatory diagnostic testing, and as an initial test to aid in the diagnosis of individuals with suspected cystic fibrosis. This test is not indicated for use for newborn screening, fetal diagnostic testing, pre-implantation testing, or for standalone diagnostic purposes. The test includes 139 pathogenic variants, including the 23 ACMG/ACOG recommended common CFTR variants. The increased number of variants improves the detection rate across a wider spectrum of patient ethnicities.

Clinical Limitation

The test does not include all known pathogenic variants of CFTR. A negative result reduces but does not eliminate the risk of carrier status or cystic fibrosis. Residual risk after a negative test varies with ethnicity, which influences both the carrier rate and the test's detection rate.