Simultaneous quantification of t(14;18) and HPRT exon 2/3 deletions in human lymphocytes

Specific recurring chromosomal translocations and deletions are found in a variety of cancers. In hematopoietic malignancies, many of these chromosomal aberrations result from mistakes involving V(D)J recombination. V(D)J recombination is required for the formation of functional T-cell receptor genes in T cells and antibody genes in B cells. This is an inherently dangerous process, however, because double-strand breaks are introduced into the chromosomes. Molecular evidence indicates that failure of the fidelity of this process results in the activation of proto-oncogenes or the inactivation of tumor suppressor genes. Here we describe sensitive, quantitative PCR assays for the measurement of such events in human lymphocytes. One assay measures the frequency of t(14;18) translocations that result in the dysfunctional regulation of the antiapoptotic gene BCL-2. The other assay measures the frequency of a deletion caused by illegitimate V(D)J recombination in the X-linked HPRT gene.