BACKGROUND: It has recently been shown that t (12;21) (p13;q 22) is the most common molecular @entity74 in childhood @entity981 ( @entity981 ). We have analyzed this translocation in an attempt to evaluate its incidence and to monitor @entity41 ( @entity41 ) with t (12; 21) rearrangement by detection of @entity9604 - @entity5316 transcript in @entity1 with @entity981 . PROCEDURE: All cryopreserved bone marrow samples were analyzed using a nested reverse transcription-polymerase chain reaction (RT-PCR) method. @entity9604 - @entity5316 transcripts were searched for in 34 @entity981 @entity1 , including six in relapse consecutively diagnosed at our institution between 1991 and 1997. RESULTS: @entity9604 - @entity5316 transcripts were found in five (19%) of 27 @entity1 with B precursor @entity981 . The @entity1 with @entity1861 , chromosome 11q23 rearrangement and @entity981 @entity1 did not express @entity9604 - @entity5316 transcripts. Moreover, @entity41 in five @entity1 with @entity9604 - @entity5316 transcripts were analyzed in serial samples. Although @entity9604 - @entity5316 transcripts disappeared soon after the beginning of chemotherapy in three of the five @entity1 , one @entity1 continued to express them for up to 21 months without recurrence and remained in continuous complete remission for seven years after the cessation of chemotherapy. The remaining @entity1 was admitted to our hospital after the second relapse but died following a failure to induce complete remission. CONCLUSION: For most @entity1 , the presence of @entity9604 - @entity5316 transcripts suggests excellent chemosensitivity and a favorable prognosis, but some @entity1 with these transcripts have a different outcome. The present study suggests the possibility that a persistence of @entity41 is not necessarily related to a relapse of @entity981 with @entity9604 - @entity5316 fusion. The prognostic significance of @entity9604 - @entity5316 transcript remains controversial. Further studies are needed to evaluate the relation between the @entity9604 - @entity5316 transcript and prognosis.

Persistence of XXXX - @entity5316 transcript in @entity981 in long-term remission.

@entity1 :: ('9606', 'Species') :: ['patients', 'patient'] @entity1861 :: ('25', 'Gene') :: ['BCR-ABL'] @entity981 :: ('MESH:D054198', 'Disease') :: ['childhood ALL', 'T-ALL', 'ALL', 'acute lymphoblastic leukemia'] @entity41 :: ('MESH:D018365', 'Disease') :: ['MRD', 'minimal residual disease'] @entity9604 :: ('2120', 'Gene') :: ['TEL'] @entity74 :: ('MESH:D030342', 'Disease') :: ['genetic abnormality'] @entity5316 :: ('861', 'Gene') :: ['AML1']
@entity9604 :: (2120,Gene) :: ['TEL']
