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ACUTE MYELOID LEUKEMIA, FISH
Test CodeLAB3327
Quest Code
16671
CPT Codes
88271 (x2), 88275
Preferred Specimen
3 mL bone marrow or 5 mL whole blood collected in a sodium heparin (green-top) tube
Note: This test is performed in addition to routine hematologic cytogenetic analysis. 100-200 interphase nuclei are examined for loss of signal(s), consistent with deletion 7q or monosomy 7. These chromosome abnormalities are associated with myeloid disorders, and acute myelogenous leukemia. The test is useful for the evalutaion of suboptimal specimens, complex karyotypes, specimens with low miotic activity, or when a normal karyotype is obtained.
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 Container
Sodium heparin (green-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.
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Received frozen
Methodology
Fluorescence in situ Hybridization (FISH)
FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.
Setup Schedule
Mon-Thurs
Reference Range
See Laboratory Report
Clinical Significance
This fluorescence in situ hybridization (FISH) assay detects monosomy 7 and deletion in chromosome 7q31 (D7S522 locus). The results of this test may aid in the diagnosis and prognostic assessment of myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML).
Monosomy 7 and del(7q) are recurrent genetic abnormalities associated with myeloid disorders, including MDS and AML. In the diagnosis of MDS, monosomy 7 and del(7q) are considered MDS-associated karyotypes; the presence of one of them can be used to help establish the diagnosis [1]. According to the Revised International Prognostic Scoring System (IPSS-R), the presence of del(7q) in patients with MDS indicates intermediate cytogenetic risk, while the presence of monosomy 7 or double abnormalities including del(7q) or monosomy 7 indicates poor cytogenetic risk [2]. In patients with AML, the presence of monosomy 7 indicates poor/adverse prognosis [3]. Monosomy 7, 7q deletion, and loss of 7q are defining cytogenetic abnormalities of AML, myelodysplasia-related (AML-MR) [4].
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. National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®). Myelodysplastic syndromes. Version 1.2023. Updated September 12,2022. https://www.nccn.org
2. Greenberg PL, et al. Blood. 2012;120(12):2454-2465.
3. National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®). Acute myeloid leukemia. Version 4.2023. Updated July 11, 2023. https://www.nccn.org
4. Khoury DJ, et al. Myeloid proliferations and neoplasms. In: WHO Classification of Tumours Editorial Board. The World Health Organization Classification of Haematolymphoid Tumours. 5 Beta V2 ed. IARC Press; 2022:chap 2. Accessed June 16, 2023. https://tumourclassification.iarc.who.int
Monosomy 7 and del(7q) are recurrent genetic abnormalities associated with myeloid disorders, including MDS and AML. In the diagnosis of MDS, monosomy 7 and del(7q) are considered MDS-associated karyotypes; the presence of one of them can be used to help establish the diagnosis [1]. According to the Revised International Prognostic Scoring System (IPSS-R), the presence of del(7q) in patients with MDS indicates intermediate cytogenetic risk, while the presence of monosomy 7 or double abnormalities including del(7q) or monosomy 7 indicates poor cytogenetic risk [2]. In patients with AML, the presence of monosomy 7 indicates poor/adverse prognosis [3]. Monosomy 7, 7q deletion, and loss of 7q are defining cytogenetic abnormalities of AML, myelodysplasia-related (AML-MR) [4].
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. National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®). Myelodysplastic syndromes. Version 1.2023. Updated September 12,2022. https://www.nccn.org
2. Greenberg PL, et al. Blood. 2012;120(12):2454-2465.
3. National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®). Acute myeloid leukemia. Version 4.2023. Updated July 11, 2023. https://www.nccn.org
4. Khoury DJ, et al. Myeloid proliferations and neoplasms. In: WHO Classification of Tumours Editorial Board. The World Health Organization Classification of Haematolymphoid Tumours. 5 Beta V2 ed. IARC Press; 2022:chap 2. Accessed June 16, 2023. https://tumourclassification.iarc.who.int
Performing Laboratory
| Quest Diagnostics Nichols Institute-Chantilly VA |
| 14225 Newbrook Drive |
| Chantilly, VA 20151-2228 |
Last Updated: September 8, 2021
