Reference Interval:
By report
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| Interpretive Data: |
Background information for Cystic Fibrosis (CFTR) 32 Mutations with Reflex to Sequencing and Reflex to Deletion/Duplication
Characteristics: Chronic sino-pulmonary disease, gastrointestinal malabsorption/pancreatic insufficiency, and obstructive azoospermia. Findings are often limited to a single organ system such as isolated pancreatitis, bilateral absence of the vas deferens, nasal polyposis, or bronchiectasis in non-classic cystic fibrosis (CF).
Incidence of Classic CF: 1 in 3,000 Caucasians or Ashkenazi Jewish, 1 in 8,000 Hispanics, 1 in 15,000 African Americans, 1 in 32,000 Asians.
Incidence of Nonclassic CF: Unknown.
Inheritance: Autosomal recessive.
Penetrance: High for severe mutations, variable for mild/moderate mutations.
Cause of Classic CF: Two deleterious CFTR mutations on opposite chromosomes.
Cause of Nonclassic CF: Typically one severe and one mild/moderate CFTR mutations on opposite chromosomes.
Mutations Tested in Panel: G85E, R117H, R334W, R347P, R347H, 394delTT, A455E, I507del, F508del, V520F, G542X, S549N, S549R, G551D, R553X, R560T, 621+1G>T, 711+1G>T, 1078delT, R1162X, W1282X, N1303K, 1717-1G>A, 1898+1G>A, 2183AA>G, 2184delA, 2789+5G>A, 3120+1G>A, 3659delC, 3849+10kbC>T, 3876delA, 3905insT. For specimens positive for R117H, the IVS-8/poly T is analyzed by sequencing.
Clinical Sensitivity for reflex: 99 percent.
Methodology for Panel: PCR, oligonucleotide ligation assay (OLA), fluorescent hybridization probes, and capillary electrophoresis.
Methodology for Sequencing: Bidirectional sequencing of the CFTR coding region and intron-exon boundaries.
Methodology for Deletion/Duplication: Multiplex ligation-dependent probe amplification (MLPA) to detect large CFTR coding region deletions/duplications.
Analytical Sensitivity and Specificity: 99 percent.
Limitations: Rare diagnostic errors can occur due to primer and probe site mutations. The breakpoints of large deletions/duplications will not be determined. Regulatory region and intronic mutations will not be detected.
Counseling and informed consent are recommended for genetic testing. Consent forms are available online at www.aruplab.com.
Please refer to Statement C in the Compliance Statements section in the front of the Laboratory Test Directory.
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| Note: |
If the CF 32 mutation panel identifies less than two deleterious mutations, CFTR gene sequencing will be performed. After CFTR gene sequencing, if less than two deleterious mutations are identified, the CFTR deletion/duplication assay will be performed.
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| CPT Code(s): |
83891 Isolation; 83900 Multiplex amplification; 83901 x30 Additional amplification; 83914 x32 OLA; 83909 Capillary electrophoresis; 83912 Interpretation and report. If reflexed to sequencing, add 83891 Isolation; 83898 x32 Amplification; 83904 x32 Sequencing; 83909 Capillary electrophoresis. If reflexed to Deletion/Duplication, add 83896 Nucleic acid probes; 83898 Amplification; 83914 Extension; 83909 Capillary electrophoresis - Additional CPT code modifiers may be required for procedures performed to test for oncologic or inherited disorders.
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