Table 1. Risk stratification.

Risk group	Definition
Low risk (LR)	Patients <2 years old at diagnosis with GATA1 mutation, achieving CR and negative FCM-MRD after Induction 1 (BMA-2)
Standard risk (SR)	Patients who do not meet the criteria for LR, MRD-HR or HR
MRD high risk (MRD-HR)	Patients with CR after Induction 1 and positive FCM-MRD (BMA-2)
High risk (HR)	Patients without CR after Induction 1 (BMA-2)

Patients who achieve CR but have unevaluable FCM-MRD, and those with negative FCM-MRD and negative or indeterminate GATA1 mutation status by Sanger sequencing, are classified as SR.

BMA, bone marrow aspiration; CR, complete remission; FCM, flow cytometry; MRD, measurable residual disease.