The CBFB Breakapart Probe mix consists of two distinct probes. The red probe (292kb) is centromeric to the CBFB gene and extends beyond the RH104363 marker to cover part of the DYNC1LI2 gene and includes the markers SHGC-60620 and SHGC-58067. The green probe (309kb) is telomeric to the CBFB gene and extends through the marker RH78922 beyond the ZDHHC1 gene to a region telomeric to the marker RH11782.
The CBFB (core-binding factor subunit beta) gene is located at 16q22; it is most commonly rearranged due to the inversion inv(16)(p13.1q22) or the translocation t(16;16)(p13.1;q22). Rarely, translocations of 16q22 with various other gene partners have been reported, whilst deletion of the band 16q22 has also been reported1.
Acute myeloid leukaemia with CBFB::MYH11, from the inv(16)(p13.1q22) or t(16;16)(p13.1;q22), form a recognised disease entity according to the World Health Organisation (WHO) classification of myeloid neoplasms and acute leukaemia2. These rearrangements are frequently found in patients with a myelomonocytic subtype with increased bone marrow eosinophils and are found in 5-8%2 of AMLs. Cases of therapy-related AML may also have this rearrangement2,3.
Inversion inv(16)(p13.1q22) or translocation t(16;16)(p13.1;q22) produce CBFB::MYH11 gene rearrangements, and are classed as a favourable cytogenetic risk group in patients with AML4,5,6.
The CytoCell® CBFB Breakapart Probe is a qualitative, non-automated, fluorescence in situ hybridisation (FISH) test used to detect chromosomal rearrangements in the 16q22 region on chromosome 16 in Carnoy’s solution (3:1 methanol/acetic acid) fixed haematologically-derived cell suspensions from patients with confirmed or suspected acute myeloid leukaemia (AML).
This product is designed as an adjunct to other clinical and histopathological tests in recognised diagnostic and clinical care pathways, where knowledge of CBFB rearrangement status would be important for clinical management.
This device is designed to detect rearrangements with breakpoints in the region bounded by the red and green clones in this probe set, which includes the CBFB gene. Breakpoints outside this region or variant rearrangements wholly contained within this region may not be detected with this product.
This device is not intended for: use as a stand-alone diagnostic, use as a companion diagnostic, prenatal testing, population-based screening, near-patient testing, or self-testing.
This device has not been validated for sample types, disease types, or purposes outside of those stated in the intended purpose.
It is intended as an adjunct to other diagnostic laboratory tests and therapeutic action should not be initiated on the basis of the FISH result alone.
Reporting and interpretation of FISH results should be performed by suitably qualified staff, consistent with professional standards of practice, and should take into consideration other relevant test results, clinical and diagnostic information.
This device is intended for laboratory professional use only.
Failure to adhere to the protocol may affect the performance and lead to false positive/negative results.
Not only do CytoCell offer an extensive range of high-quality FISH probes, the customer support is also excellent — providing fast access to all the probes I need. The probes are highly consistent with bright signals allowing easy scoring of results.
Dr Eric Crawford
Senior Director, Genetics Associates Inc., USA