Figure 2.

Comparative analysis of the mutation frequency in the BCL-6 5′-noncoding region and IgV_H segments of B cell lymphoid malignancies. Five cases representative of the major histologic subtypes and showing BCL-6 alterations upon SSCP analysis were randomly selected, along with five mantle cell lymphomas. A 742-bp region of the BCL-6 first intron and the rearranged IgV_H genes from the same patients were amplified and directly sequenced. Filled and empty circles represent the frequency of mutations in the two loci. The majority of cases in each category harbored one to two nucleotide substitutions (0.068–0.13%); particularly high values were found in one FL (n = 9, 0.6%), one BL (n = 16, 1.1%), and various DLCL cases (n = 5–24, 0.34–1.6%).