E2A/PBX1

E2A (TCF3)-PBX1 fusion gene is one of the most common translocations observed in acute lymphoblastic leukemia (ALL). It is observed in 3-6% of pediatric and 3% of adult ALL patients; and is strongly associated with a pre-B ALL immunophenotype. Two types of transcripts are associated with the E2A-PBX1 fusion. Frequently an exon13E2A/exon2PBX1 fusion is observed, but in 10-15% of the cases the transcript size is detected to be 27 bp longer due to a transcript variant. It is important to perform molecular diagnostic screening for the presence of t(1;19), along with t(9;22), t(4;11)and t(12;21) in pediatric ALL to determine prognosis and therapeutic approaches.