Test Method


Disease Long Name

Acute Myeloid Leukemia

Disease Abbreviation


CPT Code

88374 and 88377

Probes / Test Description

The CBFB-MYH11 t(16;16)(p13.1;q22.1) is a dual fusion translocation probe.

The pericentric inv(16)(p13.1q22.1) and the translocation t(16;16) (p13.1;q22.1) that are typically associated with acute myeloid leukemia, typically with eosinophilia give rise to the CBFB::MYH11 fusion gene. The CBFB (core-binding factor beta subunit) is located at 16q22.1, while the MYH11(myosin heavy chain 11) is located at 16p13.1. Conventional cytogenetics detection of abnormalities associated with chromosome 16 can be difficult. FISH probes with a break apart design might overlook this cryptic rearrangement because no separation of flanking regions of CBFB occurs, whereas dual fusion translocation FISH probes are indicating this kind of cryptic rearrangement. Furthermore, the dual fusion probe can also detect other translocations involving CBFB and another gene other than MYH11, FISH is a complementary method for the detection of inv(16)/t(16;16) increasing the sensitivity in combination with conventional cytogenetics. Furthermore, FISH is a valuable tool for cases without assessable metaphases. FISH is highly recommended to characterize unusual abnormalities of chromosome 16 and to confirm the CBFB::MYH11 fusion or an alternate translocation.

The CBFB::MYH11 fusion is classified as a favorable cytogenetic risk group in acute myeloid leukemia (AML), if a KIT mutation is not present.

Specimen Requirements

  • Bone marrow aspirate: 2-3 mL in sodium heparin (green top) preferred, or 1-2 mL in EDTA (purple top)
  • Peripheral blood: 3 mL in sodium heparin (green top) preferred, or 3 mL in EDTA (purple top)
  • Fresh Tissue: Multiple 2-3 mm pieces of tissue in RPMI transport media (optimum RPMI to tissue ratio is 15:1; (multiple vials are acceptable)
  • Formalin-Fixed Paraffin-Embedded Tissue: Minimum 0.2 x 0.2 x 0.2 cm tissue, non-decalcified tissue only

Storage & Transport

Ship specimen the same day whenever possible, with refrigerated (not frozen) cold pack.

Label all tubes with at least two unique patient identifiers. Slides require one patient identifier. Identifiers include name, DOB, specimen ID# or medical record#.

Turnaround time

3 – 5 days

Level of Service