Distinct molecular genetics of chronic lymphocytic leukemia in Taiwan: clinical and pathogenetic implications.

Differences in chronic lymphocytic leukemia between the Asian and the Western population are widely known. To further clarify these ethnic differences, we profiled the molecular genetics in a cohort of 83 newly diagnosed patients from Taiwan. In detail, we assessed: (i) the usage and the mutational status of the clonotypic immunoglobulin heavy-chain variable region () genes, (ii) the presence of VH CDR3 stereotypes, and (iii) , and mutations. The gene repertoire was biased and distinct from that observed in the West with the most common genes being , and In terms of gene mutational status, 63.8% of patients carried mutated rearrangements, whereas 22.4% of patients were assigned to stereotyped subsets (6.9% to major subsets and 15.5% to minor ones). The frequencies of , and mutations were 9.6%, 7.2%, 1.2%, and 2.4%, respectively; however, the frequency of mutations was significantly higher (20.5%). Patients with mutations or del(17p), mutations and unmutated had a worse outcome compared to the other patients. In conclusion, the differences observed in properties suggest different pathogenetic factors implicated in the development of chronic lymphocytic leukemia, while the high frequency of mutations could in part explain the dismal outcome of these patients in Taiwan.