Characterization of BCL-6 mutations in 46 representative B-cell neoplasms.

(A) Schematic representation of the BCL-6 gene. Coding and non-coding exons are indicated by filled and empty boxes, respectively. The PCR fragment amplified for mutational analysis is approximately positioned below the BCL-6 gene map and expanded in panel B to show the distribution of mutations. (B) Each line of rectangles represent the BCL-6 sequence of a different B-cell neoplasm. Each case is indicated by a numbered code, together with the corresponding diagnosis (on the left; B-CLL, B-cell chronic lymphocytic leukemia; LPL, lymphoplasmacytoid lymphoma; HCL, hairy cell leukemia; MCL, mantle cell lymphoma; FL, follicular lymphoma; B-DLCL, B-lineage diffuse large cell lymphoma). Each rectangle represents a 20 bp interval of the BCL-6 sequence; nucleotide positions are indicated in the top line. The first nucleotide of the BCL-6 cDNA was arbitrarily chosen as +1. Filled rectangles indicate the presence of mutation(s) in the corresponding 20 bp of the BCL-6 sequence. The characteristics of individual mutations are detailed on the right (eg, G549C, G → C at nucleotide position 549).