The PDGFRB product consists of a 107kb probe, labelled in red, located centromeric to the PDGFRB gene, including the D5S2618 and D5S2619 markers and a green probe, covering a 154kb region telomeric to the PDGFRB gene, including the D5S2015 marker.
Rearrangements involving the PDGFRB (platelet derived growth factor receptor beta) gene at 5q32 are reported in both myeloid and lymphoid neoplasms.
In the 2008 World Health Organization (WHO) classification of myeloid neoplasms and acute leukaemia, a new subgroup of myeloid neoplasms was introduced: Myeloid and Lymphoid Neoplasms with Eosinophilia and Abnormalities of PDGFRA, PDGFRB or FGFR1. These neoplasms constitute three specific disease groups, with some shared features1.
The myeloid neoplasms with PDGFRB rearrangements are characterised by constitutive activation of the PDGFRB gene product1. The activation is most commonly caused by a t(5;12)(q31-q33;p13) translocation which results in an ETV6-PDGFRB fusion gene. Patients with this fusion have been shown to be responsive to tyrosine kinase inhibitors (TKIs)2, which specifically inhibits the kinase activity of PDGFRB.
In B-ALL, gene expression profiling has identified an unusual genetic subgroup, the BCR-ABL1-like or Philadelphia chromosome-like (Ph-like) ALL, which represents about 15% of paediatric ALL cases and has an unfavourable outcome3,4. Patients with this expression signature are characterised by genetic alterations, such as rearrangements, mutations and deletions of a range of kinase and cytokine receptors, including PDGFRB rearrangements. Known PDGFRB partners are EBF1 at 5q33, SSBP2 at 5q14, TNIP1 at 5q33 and ZEB2 at 2q22. It is crucial to detect such rearrangements, as patients could benefit from treatment with tyrosine kinase inhibitors (TKIs)3,4,5.
I first came across CytoCell FISH probes in a previous lab I worked in and I was struck by the quality of the products. Since this time, I have been recommending and introducing CytoCell probes across all application areas — now they are the primary FISH probes used in our lab. They have an excellent range of products and their ready-to-use reagent format saves considerable time.
Medical Technologist, University of Arizona Health Network, USA