DNA rearrangements in human follicular lymphoma can involve the 5' or the 3' region of the bcl-2 gene.

Abstract

In most human follicular lymphomas, the chromosome translocation t(14;18) occurs within two breakpoint clustering regions on chromosome 18, the major one at the 3'' untranslated region of the bcl-2 gene and the minor one a 3'' of the gene. Analysis of a panel of follicular lymphoma DNAs using probes for the first exon of the bcl-2 gene indicates that DNA rearrangements may also occur 5'' to the involved bcl-2 gene. In this case the IgH locus and the bcl-2 gene are found in the order 3'' C.gamma. S.gamma./.mu. JH 5''::5'' bcl-2 3'' (where C = constant, S = switch, and JH = joining segment of the heavy chain locus), suggesting that an inversion also occurred during the translocation process. The coding regions of the bcl-2 gene, however, are left intact in all cases of follicular lymphoma studied to date.