IGH Breakapart LPH014 - Detail

In ALL, IGH is most notably involved in rearrangements involving the cMYC oncogene as a result of the t(8;14) translocation¹. However, less common rearrangements of the IGH gene are most often seen in T-ALL but can also be found in B-ALL. There are a number of stereotypical translocations involved in each of the two diseases and more are being described regularly. In T-ALL for example, IGH is observed in the t(14;14)(q11;q32) translocation (or inv(14)(q11q32) rearrangement) ² and is found in T-cell leukaemia associated with ataxia-telangiectasia (AT). However rare reports have indicated that this abnormality also occurs in B-ALL. The recurrent t(14;19)(q32;q13) translocation associated with chronic B-cell lymphoproliferative disorders, such as atypical CLL, has also been shown to occur in B-ALL and results in the juxtaposition of the IGH and BCL2 genes and subsequent over expression of BCL3³. More recently, a report suggested the involvement of IGH in a novel cryptic translocation in paediatric T-cell Acute Lymphoblastic Leukaemia (T-ALL), which also involved HOX11L2 or CSX on 5q35 brought about by a t(5;14)(q35;q32) translocation⁴. In CLL, around 20% of cytogenetically abnormal CLL patients have a detectable 14q+ marker chromosome. The markers are derived from reciprocal translocations involving a number of fusion partners from different chromosomes that fuse with the IGH gene at 14q32. Involvement of chromosomes 1, 2, 5, 6, 7, 8, 9, 11, 12, 13, 14, 17, 18, 19 and 22 have been described and the two most common translocations are IGH/BCL2 involving the t(14;18) translocation and IGH/CCND1 involving the t(11;14) translocation. With all these rearrangements having breakpoints within the IGH gene, we have designed a split probe set for IGH, which can detect any rearrangement. This involves the splitting of the IGH gene in the region between the Constant and Variable segments thereby identifying the IGH translocation partner chromosome in the less common rearrangements of this gene.

Reference:/Bibliographie/Literatur/Bibliografia

1. Moore et al., 2003. Cancer Genet Cytogenet. 141(1): 1-4
2. Liu et al., 2004. Cancer Genet Cytogenet. 152(2): 141-5
3. Robinson et al., 2004. Genes Chromosomes Cancer. 39(1): 88-92.
4. van Zutven et al., 2004. Haematologica. 89(6): 671-8