A 26-year-old man presents with fatigue, anemia, and a WBC of 90,000/uL consisting of lymphoblasts. Bone marrow flow cytometry shows TdT+, CD19+, CD10+, cytoplasmic CD79a+. Cytogenetics reveal t(9;22)(q34;q11.2). Which fusion transcript is most characteristically found in ALL with this translocation?

• A E2A-PBX1
• B e13a2 (p210) BCR-ABL1
• C e14a2 (p230) BCR-ABL1
• D e1a2 (p190) BCR-ABL1 ✓

Explanation

Although t(9;22) occurs in both CML and ALL, the breakpoint differs: ALL usually breaks in the minor-bcr region upstream of exon 1, producing the smaller p190 (e1a2) transcript, whereas CML typically yields p210. Ph positivity in ALL confers a poor prognosis and mandates tyrosine kinase inhibitor addition to chemotherapy. E2D-PBX1 arises from t(1;19), a separate ALL subtype.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.