IGH/BCL2 Translocation, Dual Fusion - Detail

This is the second most common rearrangement of IGH in CLL and is cytogenetically indistinguishable from the t(14;18) translocation observed in follicular lymphoma.

The translocation is thought to be brought about by an error in the joining function of the IGH gene, mediated by the recent observation that both IGH and BCL2 are arranged next to each other in the normal B lymphocyte¹. The translocation breakpoint at the end of the Joining (J) segment, and the subsequent fusion of the BCL2 gene to this region, results in the BCL2 gene coming under the regulatory control of those processes normally involved in maintenance of IGH gene activity. The BCL2 gene itself has been shown to be involved in the regulation of apoptosis.

References:

1. Roix et al., Nature Genetics 2003;34(3):287-91