FISH, CLL, ATM, Deletion 11q22.3

Test Code
16666


CPT Codes
88271, 88275

Includes
If results are not possible, the test order may be canceled and replaced by code %39650 - Cytogenetics Communication.


Preferred Specimen
3 mL bone marrow or 5 mL whole blood collected in a sodium heparin (green-top) tube


Minimum Volume
1 mL bone marrow • 3 mL whole blood


Other Acceptable Specimens
Sodium heparin (royal blue-top) tube • Sodium heparin lead-free (tan-top) tube


Transport Temperature
Room temperature


Specimen Stability
Specimen viability decreases during transit. Send specimen to testing lab for viability determination. Do not freeze. Do not reject.


Methodology
Fluorescence in situ Hybridization (FISH)

Setup Schedule
Set up: Daily; Report available: 5 days


Clinical Significance
This fluorescence in situ hybridization (FISH) assay detects deletion of the ATM gene region in chromosome 11q22.3. The results of this test may aid in the prognostic assessment and treatment selection for chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL).

The most common genetic abnormalities of CLL/SLL are del(13q), del(11q), trisomy 12, and del (17p). At least one of these 4 genetic abnormalities can be detected with FISH in >80% of patients with CLL/SLL [1]. Evaluation of these frequent genetic abnormalities is recommended for the investigation of prognosis [2] and may inform treatment decisions [3]. Del(11q) results in the loss of the ATM gene and can be detected with FISH in 18% of patients with CLL/SLL [1]. The presence of del(11q) is associated with marked lymphadenopathy and unfavorable prognosis [2,3].

A combination of genetic techniques is often involved in identifying genetic abnormalities. FISH testing is complementary to conventional cytogenetic analysis (karyotyping) and can be used to detect common cytogenetic abnormalities. However, because FISH is limited to probing specific chromosomal regions, it does not replace conventional cytogenetic analysis or chromosomal microarray for screening unknown abnormalities.

The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings.

References
1. Dohner H, et al. N Engl J Med. 2000;343(26):1910-1916.
2. Naresh KN, et al. B-cell lymphoid proliferations and lymphomas. In: WHO Classification of Tumours Editorial Board. The World Health Organization Classification of Haematolymphoid Tumours. 5 Beta V2 ed. IARC Press; 2022:chap 4. Accessed June 16, 2023. https://tumourclassification.iarc.who.int
3. National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®). Chronic lymphocytic leukemia/small lymphocytic lymphoma. Version 3.2023. Updated June 12, 2023. https://www.nccn.org




The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.