30006000330066003300660036007200
5T/box(Ⅰ-01)10T/box(Ⅰ-02)5T/box(Ⅱ-01)10T/box(Ⅱ-02)5T/box(Ⅲ-01)10T/box(Ⅲ-02)5T/box(Ⅳ-01)10T/box (IV-02)

30006000330066003300660036007200
5T/box(Ⅰ-01)10T/box(Ⅰ-02)5T/box(Ⅱ-01)10T/box(Ⅱ-02)5T/box(Ⅲ-01)10T/box(Ⅲ-02)5T/box(Ⅳ-01)10T/box (IV-02)
The E2A gene can be fused to the PBX1 and HLF genes; E2A/PBX1 is more common (5%), while E2A/HLF is less common (1%);
It accounts for about 5% of childhood ALL; both fusions imply a poor prognosis and a high risk of recurrence;
Karyotyping tends to lead to 20-25% missed diagnoses, a shortcoming that can be overcome by FISH;
These patients often relapse early after standard chemotherapy.