Cystic Fibrosis Transmembrane Conductance Regulator, CFTR, Full Gene Analysis, Varies

Casandra

Casandra Test Code MC82498Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID CFTRNCPT Codes 81223, 88233, 88240

Cystic Fibrosis Transmembrane Conductance Regulator, CFTR, Full Gene Analysis, Varies

Clinical Use

Use

This test is useful for follow-up testing to identify variants in individuals with a clinical diagnosis of cystic fibrosis (CF), identifying genetic variants in individuals with atypical presentations of CF, and identifying genetic variants where detection rates by targeted variant analysis are low or unknown. Identifying patients who may respond to cystic fibrosis transmembrane conductance regulator (CFTR) potentiator therapy may also be part of its clinical purpose.

Special Instructions

This test is not the preferred test for cystic fibrous carrier screening. Additional testing requirements indicate that all prenatal specimens must be accompanied by a maternal blood specimen. For cord blood specimens, maternal cell contamination (MCC) studies are available. Consultation with the laboratory is required for all prenatal testing, with instructions available by calling 800-533-1710.

Limitations

Next-generation sequencing may not detect all types of genomic variants. Technical limitations include regions of homology, high guanine-cytosine (GC) content, and repetitive sequences. The test is validated to detect 95% of deletions up to 75 base pairs and insertions up to 47 base pairs. However, Delins of 40 or more bp including mobile element insertions may be less reliably detected. The test may not detect low levels of mosaicism or differentiate between somatic and germline variants. Reclassification of variants is not routine, and if the patient has had an allogeneic hematopoietic stem cell transplant, results may be inaccurate.

Test Details

New York Approved