Test Code

F BCR ABL

Test Synonyms

Philadelphia chromosome, t(9;22)(q34;q11.2)

Associations

Chronic Myelogenous Leukemia (CML), Acute Lymphoblastic Leukemia (ALL), Acute Myeloid Leukemia (AML), Myelodsplastic Syndrome (MDS), Myeloproliferative Disorder (MPD)

Methodology

Fluorescence in situ Hybridization (FISH)

Turnaround Time

3-5 days

Specimen Requirements

5mL peripheral blood in sodium heparin
3mL bone marrow in sodium heparin
Fixed cytogenetically prepared cells in sterile centrifuge tube with pellet visible in 3:1, Methanol:Acetic Acid

Specimen Stability

Storage & Handling

4°C to 25°C during transit, but specimens may be transported on refrigerated gel packs. Do not allow the gel pack to come in contact with the specimen. Do not freeze. Extreme temperatures should be avoided.

Causes for Rejection

Clotted specimen; Specimen exposed to extreme temperature; Anticoagulant toxic to cells; Insufficient number of cells

Reference Range

FISH analysis detects presence or absence of t(9;22).

Description

Chronic myelogeneous leukemia (CML) is a stem cell disorder characterized by the cytogenetic abnormality of t(9;22)(q34;q11.2), which progresses from a chronic phase to an accelerated phase, and/or a blast phase of myelocytic or lymphoid phenotype. This progression is frequently preceded or accompanied by recurring secondary chromosomal abnormalities.

The abnormality, t(9;22)(q34;q11) has been identified in 84% of typical CML, 13% acute lymphoblastic leukemia (ALL), 1% acute myeloid leukemia (AML) and 2% MDS. Ph+ AMLs are increasingly being reported with either M-BCR or m-BCR gene rearrangements, similar to those found with Ph+ ALL lending support to the notion that Ph+ AML are distinct entities and not merely blastic phases of undiagnosed CML. This is further supported by the existence of Ph+ MDS cases.

FISH can detect this translocation in either interphase or metaphase cells.

References

1. Wang et al. (2004). Determination of secondary chromosomal aberrations of chronic myelocytic leukemia. Cancer Genet Cytogenet. 153(1):53.
2. Keung et al. (2004). Philadelphia chromosome positive myelodysplastic syndrome and acute myeloid leukemia – retrospective study and review of literature. Leukemia Res. 28(6):579.
3. Haigh. (2004). Fluorescence in situ hybridization characterization of different cryptic BCR-ABL rearrangements in chronic myeloid leukemia. Cancer Genet Cytogenet. 155(2):132.
4. Sinclair PB et al. (2000). Large deletions at the t(9;22) breakpoint are common and may identify a poor-prognosis subgroup of patients with chronic myeloid leukemia. Blood. 95(3):738.