Used For

The majority of follicular lymphomas are characterized by t(14;18) (q32;q21). This translocation joins the BCL2 gene on chromosome 14, resulting in the overproduction of the BCL2 protein, a potent apoptosis inhibitor. There are two common breakpoint regions involving BCL2 with approximately 65% of the breakpoints occurring at the major breakpoint region (MBR) and approximately 10% occurring at the minor cluster region (mcr). The BCL2-IGH translocation is also observed in 20% to 30% of diffuse large B-cell lymphomas. The ability to detect the t(14;18) translocation by means of polymerase chain reaction (PCR) allows for rapid assessment of the presence of this translocation. This is of significant clinical utility for defining the cause of the lymphoma and for monitoring minimal residual disease.

Limitations

The absence of a detectable fusion product does not exclude the presence of a rearrangement outside of the two breakpoint regions evaluated, or the presence of a B-cell lymphoma without an underlying BCL2-IGH translocation. In addition, it is important to note that the BCL2-IGH gene rearrangement has also been detected at low levels in some apparently benign hyperplastic lymphoid tissues.