Analysis of hypermutation of the 5' noncoding region in the BCL-6 gene

Objective To investigate BCL-6 gene mutations in Chinese populations with B-cell non-Hodgkin's lymphoma. Methods Polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE) and direct DNA sequencing were used to identify mutations in the 5' noncoding region of the BCL-6 gene in a total of 40 cases of diffuse large-cell lymphoma (DLCL) and follicular lymphoma (FL). Results Nine cases were found to have base substitutions. The incidence of BCL-6 gene mutation and the frequency of single-base changes were approximately 25.7% and (0.56 - 1.10) x 10(-2)/bp, respectively. Conclusions The 5' regulatory region of the BCL-6 gene undergoes frequent somatic hypermutation during lymphomagenesis and the identification of BCL-6 gene hypermutations provides a molecular marker for confirmatory diagnosis of B-NHL.