ARUP's Laboratory Test Directory

Cystic Fibrosis (CFTR) 5T Mutation : 0056003
[ image for: Patient History For Cystic Fibrosis (CF) Testing]
Patient History For Cystic Fibrosis (CF) Testing
  


Mnemonic: IVS-8

Ordering Recommendation: Determine the presence of the CFTR 5T variant.
Methodology: Polymerase Chain Reaction/Fragment Analysis
Performed: Sun-Sat
Reported: 3-7 days
Specimen Required: Collect: Lavender (EDTA), pink (K2EDTA), or yellow (ACD Solution A or B).

Specimen Preparation: Transport 3 mL whole blood. (Min: 1 mL)

Storage/Transport Temperature: Refrigerated.

Stability (collection to initiation of testing): Ambient: 72 hours; Refrigerated: 5 days; Frozen: Unacceptable
Interpretive Data: Background Information for Cystic Fibrosis (CFTR) 5T Mutation
Characteristics: The 5T mutation is a mild cystic fibrosis transmembrane regulator (CFTR) mutation resulting in improper mRNA splicing removing exon 9 from 90 percent of the CFTR protein. It is commonly observed in combination with a severe mutation on the other allele in individuals with a single CF symptom such as congenital bilateral absence of the vas deferens, bronchiectasis, or idiopathic pancreatitis.
Allele Frequency: 5 percent.
Penetrance: Variable
Cause: 5T residues in the eighth CFTR intron instead of the more common seven.
Mutation tested: 5T mutation (c.1210-12T[5_9]) in CFTR.
Methodology: Polymerase chain reaction, oligonucleotide ligation assay (OLA), fluorescent hybridization probes, and capillary electrophoresis.
Analytical Sensitivity and Specificity: 99 percent.
Limitations: Mutations within the primer/probe regions could affect the analytical sensitivity of this assay



Counseling and informed consent are recommended for genetic testing. Consent forms are available online at www.aruplab.com.

See Compliance Statement C: www.aruplab.com/CS
CPT Code(s): 81224