Hematologic Diseases

Cytogenetic abnormalities commonly associated with multiple myeloma (MM) are detected by fluorescence in situ hybridization (FISH). Probes for CKS1B-CDKN2C (1p32.3/1q21.3), 5q (5q-/-5/+5), 13q (13q-/-13), IGH (14q32.3), and TP53 (17p13.1) are included in the Myeloma Reflex FISH Profile (Enriched). If IGH positive, Genoptix will reflex to IGH/FGFR3 t(4;14), IGH/CCND1 t(11;14), IGH/MAF t(14;16) and IGH/MAFB t(14;20). Plasma cells are enriched from patient’s specimen using immunomagnetic enrichment technology with CD138 antibody.

disease state indication(s)
Multiple myeloma (MM), monoclonal gammopathy of undetermined significance (MGUS)

clinical use
The Myeloma Reflex FISH Profile (Enriched) detects cytogenetic abnormalities that can help genetically subclassify and risk stratify patients with multiple myeloma (MM). Standard-risk cytogenetic abnormalities include hyperdiploidy and t(11;14), while high-risk cytogenetic abnormalities include del(17/17p), t(4;14), t(14;16),t(14;20), and gain(1q) [1]. FISH analysis on specimens enriched for plasma cells can enhance the ability to detect abnormalities, particularly in cases with a low percentage of monoclonal plasma cells.

References:
1. Sonneveld P, et al. Treatment of multiple myeloma with high-risk cytogenetics: a consensus of the Internal Myeloma Working Group. Blood 2016;127:2955-2962.

methodology/product platform
Fluorescence in situ hybridization (FISH)

specimen type and requirements
Peripheral blood: 5-6 mL in sodium heparin (green-top) tube.
Bone marrow: 2-3 mL in sodium heparin (green-top) tube.
Bodily fluids: Bodily fluids for diagnostic testing of hematological cancers (subject to specimen viability). Preferred transport in equal parts RPMI.
Lymphoid tissue: Transport in RPMI.
FFPE tissue: no decalcification (except for centromere as well as locus specific FISH probes).
Note: Use refrigerated cold pack for transport. Make sure cold pack is not in direct contact with specimen.
DO NOT FREEZE.

Probe Prioritization: If samples are insufficient to complete the whole FISH panel, Genoptix will prioritize testing in the following order:
1) If ≤ 5 wells, IGH/FGFR3, TP53, CKS1B-CDKN2C, IGH/MAF, and IGH/MAFB; or
2) if >5 wells, CKS1B-CDKN2C, 5p, 13q, TP53, and IGH, unless directed otherwise by the client.
The remaining probes will be completed on the unenriched cells if available.

turnaround time
Global (TC & PC): 5 days

cpt code(s)
88368 (x1)
88377 (x4)
88112-TC (x1)

*If IGH is (+) then 88368 (x1), 88377 (x8), 88112-TC (x1)

medicare moldx cpt code
Not applicable

regulatory classification
Laboratory developed test (LDT)

ordering option
Global (TC & PC)