| 1. Cytopenia defined by standard hematologic reference values |
| 2. Presence of a somatic SF3B1 mutation |
| 3. Isolated erythroid or multilineage dysplasia, with or without RS |
| 4. BM blasts <5% and PB blasts <1% |
| 5. WHO criteria not fulfilling any other category |
| 6. Normal karyotype or any cytogenetic abnormality other than del(5q), monosomy 7, inv(3) or abnormal 3q26, complex (≥3) |
| 7. Presence of any additional somatic gene mutation other than RUNX1 and/or EZH2* |
| 1. Cytopenia defined by standard hematologic reference values |
| 2. Presence of a somatic SF3B1 mutation |
| 3. Isolated erythroid or multilineage dysplasia, with or without RS |
| 4. BM blasts <5% and PB blasts <1% |
| 5. WHO criteria not fulfilling any other category |
| 6. Normal karyotype or any cytogenetic abnormality other than del(5q), monosomy 7, inv(3) or abnormal 3q26, complex (≥3) |
| 7. Presence of any additional somatic gene mutation other than RUNX1 and/or EZH2* |
Additional JAK2V617F, CALR, or MPL mutations strongly support the diagnosis of myelodysplastic syndrome/myeloproliferative neoplasm with ring sideroblasts and thrombocytosis (MDS/MPN-RS-T). Adapted from Malcovati et al.22