XL CBFB/MYH11 plus consists of a green-labeled probe hybridizing to the MYH11 gene region at 16p13.1 and an orange-labeled probe hybridizing to the CBFB gene region at 16q22.

Probe maps are created in accordance with the intended purpose of the product. Solid colored bars do not necessarily indicate that the probe fully covers the indicated genomic region. Therefore, caution is advised when interpreting results generated through off-label use. Probe map details based on UCSC Genome Browser GRCh37/hg19. Map components not to scale. Further information is available on request.

Acute myeloid leukemia (AML) with inv(16)(p13.1;q22) and t(16;16)(p13.1;q22) is listed in the World Health Organization (WHO) classification of tumors of the haematopoietic and lymphoid tissues. These recurrent rearrangements are present in about 10% of young AML patients. In cases with inv(16)/t(16;16), the core binding factor b (CBFB) gene on 16q22 is fused with the smooth muscle myosin heavy chain gene (MYH11) on 16p13.1. Patients carrying inv(16)/t(16;16) usually have a good prognosis. Cryptic insertions with no indication in cytogenetic analyses have been published. In these cases, a partial insertion of MYH11 into CBFB or a partial insertion of CBFB into the MYH11 gene was observed.
FISH probes with a break apart design might overlook this cryptic rearrangement because no separation of flanking regions of CBFB occurs, whereas translocation/dual fusion FISH probes are indicating this kind of cryptic rearrangement. 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.

Clinical Applications

• Acute Myelogenous Leukemia (AML)

XL CBFB/MYH11 plus hybridized to bone marrow cells. One aberrant interphases is shown. A partial insertion of MYH11 into CBFB results in two green, one orange and one green/orange colocalization/fusion signal.

• Fröhling et al (2005) Heamatologica 90:194-199
• Van Obbergh et al (2014) Cancer Genetics 207:231-232
• Zhang et al (2017) Adv in Mod Onc Res 3:12-14

• Utility and performance of bacterial artificial chromosomes-on-beads assays in chromosome analysis of clinical prenatal samples, products of conception and blood samples.
• A child with multiple congenital anomalies due to partial trisomy 7q22.1 → qter resulting from a maternally inherited balanced translocation: a case report and review of literature.
• Distinct roles of ATM and ATR in the regulation of ARP8 phosphorylation to prevent chromosome translocations.
• Heterogeneous MYCN amplification in neuroblastoma: a SIOP Europe Neuroblastoma Study.
• Immense random colocalization, revealed by automated high content image cytometry, seriously questions FISH as gold standard for detecting EML4-ALK fusion.
• Fluorescence in situ hybridisation assays designed for del(7q) detection uncover more complex rearrangements in myeloid leukaemia cell lines
• Detection of t(7;12)(q36;p13) in paediatric leukaemia using dual colour fluorescence in situ hybridisation.
• A rare case of t(11;22) in a mantle cell lymphoma like B-cell neoplasiaresulting in a fusion of IGL and CCND1: case report.
• Genomic DNA-chip hybridization in t(11;14)-positive mantle cell lymphomas shows a high frequency of aberrations and allows a refined characterization of consensus regions.