JMML, JMML-like neoplasms, and Noonan syndrome-associated myeloproliferative disorder
| . | PB/BM blasts . | Mutation . | Secondary mutations . | Karyotype . |
|---|---|---|---|---|
| JMML | <20% PB <20% BM | PTPN11, NRAS, KRAS, RRAS, NF1*, CBL† | Any | Any (monosomy 7 in 25%) |
| JMML-like neoplasms | <20% PB <20% BM | Absence of RAS-pathway mutation | Any | Any |
| Noonan syndrome–associated myeloproliferative disorder | <20% PB <20% BM | PTPN11,‡NRAS,‡KRAS,‡RIT1‡ | None | Normal§ |
| . | PB/BM blasts . | Mutation . | Secondary mutations . | Karyotype . |
|---|---|---|---|---|
| JMML | <20% PB <20% BM | PTPN11, NRAS, KRAS, RRAS, NF1*, CBL† | Any | Any (monosomy 7 in 25%) |
| JMML-like neoplasms | <20% PB <20% BM | Absence of RAS-pathway mutation | Any | Any |
| Noonan syndrome–associated myeloproliferative disorder | <20% PB <20% BM | PTPN11,‡NRAS,‡KRAS,‡RIT1‡ | None | Normal§ |
Germline mutation with additional aberration resulting in biallelic inactivation of the NF1 gene.
Germline mutation with additional aberration resulting in biallelic inactivation of the CBL gene; some cases with heterozygous germ line mutation only.
Germline mutation, patients generally display syndromic features of Noonan syndrome.
In rare instances, monosomy 7 can develop.261,262