The vast majority of CML patients have a BCR-ABL translocation that yields a 210 kD (p210) oncoprotein, whereas adult Ph-positive ALL cases can present with either a p190 or a p210 oncoprotein, or both.
The authors report an unusual presentation of a Philadelphia chromosome-positive acute lymphoblastic leukemia with two unusual features: a bcr-abl fusion mRNA coding for p210 protein and a T-cell immunophenotype.
While six out of the seven P210-positive ALL samples had ABL1 promoter methylation, none of the 11 P190-positive ALL samples demonstrated ABL1 promoter methylation.
Multiplex in-cell reverse transcription-polymerase chain reaction for the simultaneous detection of p210 and p190 BCR-ABL mRNAs in chronic myeloid leukemia and Philadelphia-positive acute lymphoblastic leukemia cell lines.
In most cases of CML and some cases of Ph+ ALL the protooncogene ABL from 9q34 is translocated to the breakpoint cluster region (bcr) of the BCR gene at 22q11 to form a chimeric gene encoding a novel 210-kd protein (P210 BCR-ABL) with enhanced tyrosine kinase activity.