Key features of TAM and JMML
| . | TAM . | JMML . |
|---|---|---|
| Clinical features | Diagnosis of trisomy 21 | Male to female ratio 2:1 |
| Age ≤3 months | Most common in early childhood | |
| Jaundice and/or HSM are common | Splenomegaly in almost all patients | |
| Rash and effusions are less frequent | Lymphadenopathy and fever are common | |
| Laboratory findings | Leukocytosis | Leukocytosis |
| Circulating blasts (higher in blood than BM) | Monocytosis (≥1 × 109/L) | |
| Blast count <20% in blood and BM | ||
| Anemia is rare | Thrombocytopenia is common | |
| Genetic features | GATA1 mutation | Germline mutations/LOH: CBL, NF1 |
| Or | ||
| Somatic mutations: PTPN11, KRAS, NRAS, RRAS |
| . | TAM . | JMML . |
|---|---|---|
| Clinical features | Diagnosis of trisomy 21 | Male to female ratio 2:1 |
| Age ≤3 months | Most common in early childhood | |
| Jaundice and/or HSM are common | Splenomegaly in almost all patients | |
| Rash and effusions are less frequent | Lymphadenopathy and fever are common | |
| Laboratory findings | Leukocytosis | Leukocytosis |
| Circulating blasts (higher in blood than BM) | Monocytosis (≥1 × 109/L) | |
| Blast count <20% in blood and BM | ||
| Anemia is rare | Thrombocytopenia is common | |
| Genetic features | GATA1 mutation | Germline mutations/LOH: CBL, NF1 |
| Or | ||
| Somatic mutations: PTPN11, KRAS, NRAS, RRAS |
BM , bone marrow; HSM , hepatosplenomegaly; JMML , juvenile myelomonocytic leukemia; LOH , loss of heterozygosity; TAM , transient abnormal myelopoiesis.