ObjectiveTo 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)×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
