Lack of TEL-AML1 fusion transcript resulting from a cryptic t(12;21) in adult B lineage acute lymphoblastic leukemia in Taiwan..     ///     Cryptic t(12;21)(p12-13;q22) leading to TEL-AML1 fusion has recently been recognized as the most frequent genetic rearrangement in childhood acute lymphoblastic leukemia (ALL) in Western countries.     ///    "In this study, we assessed further the frequency of TEL-AML1 fusion as well as that of BCR-ABL in Chinese adults with ALL, using reverse transcriptase-polymerase chain reaction assays. "    ///    The lack of cases with the TEL-AML1 fusion together with the high frequency of BCR-ABL fusion could largely account for the poorer outcome of adult ALL as compared with childhood ALL..     ///    "Among the 81 cases with newly diagnosed B lineage ALL studied, none had the TEL-AML1 fusion whereas 30 had the BCR-ABL fusion. "