IGH/MAF
Methodology
FISH
Test Description and clinical significance
Probes
14q32.33/16q23.1-q23.2
Disease:
Multiple myeloma, MGUS
t(14;16) gene fusions involving the IGH gene at 14q32 and the MAF gene at 16q23 is generated during B-cell maturation in germinal centers possibly as a result of errors in the IGH switch recombination. The anomaly appears to be an early event in the genesis of plasma cell neoplasms (PCN) as it occurs in both MGUS and MM. Presence of an IGH-MAF rearrangement is a sign of poor prognosis in myeloma.
Specimen Requirements
Collection:
The ordering pathologist will decide whether to order a conventional FISH preparation or a Plasma-cell enrichment (PCE) FISH preparation.
Bone Marrow Aspirate: 1~2mL in Green top (Sodium Heparin) tube OR Lavender top (EDTA) tube. Plasma cell enrichment eligible.
Peripheral Blood: 2~5mL Green top (Sodium Heparin) tube OR Lavender top (EDTA) tube. Plasma cell enrichment eligible ONLY IF circulating plasma cells are noted in PB.
Fresh, Unfixed Tissue: Tissue in RPMI. A conventional FISH preparation will be performed as plasma cell enrichment can not be performed on fresh tissues.
Fluids: Equal parts RPMI to specimen volume. A conventional FISH preparation will be performed as plasma cell enrichment can not be performed on fresh fluid tissues.
Paraffin Block: H&E slide and paraffin block. Plasma cell enrichment can not be performed on paraffin embedded tissues. Enumeration probe types (1p36/1q25, 13q14.2/13q34, CEN9, and TP53/CEN17) are not compatible with paraffin embedded tissues.
Cut Slides: H&E slide and 1 unstained slide (cut at 4 microns) per probe. Plasma cell enrichment can not be performed on paraffin embedded tissues. Enumeration probe types (1p36/1q25, 13q14.2/13q34, CEN9, and TP53/CEN17) are not compatible with paraffin embedded tissues.
Stability:
120 Hours/48 hours
Unacceptable Conditions:
DO NOT FREEZE
Storage & Transport
Room Temperature/Refrigerated (2–8°C )
CPT(s)
88377
New York Approved
YES
TAT
2 Days
*The CPT codes provided are for informational purposes only and are based on AMA guidelines The billing party is solely responsible for correct CPT coding.
