Juvenile myelomonocytic leukaemia (JMML) is a rare clonal disorder of early childhood. Constitutive activation of the RAS pathway is the initial event in JMML. Around 90% of patients diagnosed with JMML carry a mutation in the PTPN11, NRAS, KRAS, NF1 or CBL genes. It has been demonstrated that after this first genetic event, an additional somatic mutation or epigenetic modification is involved in disease progression. The available genetic and clinical data have enabled researchers to establish relationships between JMML and several clinical conditions, including Noonan syndrome, Ras-associated lymphoproliferative disease, and Moyamoya disease. Despite scientific progress and the development of more effective treatments, JMML is still a deadly disease: the 5-year survival rate is ~50%. Here, we report on recent research having led to a better understanding of the genetic and molecular mechanisms involved in JMML.

少年骨髓单核细胞白血病（JMML）是儿童早期的罕见克隆性疾病。RAS途径的组成性激活是JMML中的初始事件。约90％被诊断患有JMML的患者携带PTPN11，NRAS，KRAS，NF1或CBL突变基因。已经证明在该第一个遗传事件之后，另外的体细胞突变或表观遗传修饰与疾病进展有关。现有的遗传和临床数据使研究人员能够建立JMML与几种临床状况之间的关系，包括Noonan综合征，与Ras相关的淋巴增生性疾病和Moyamoya疾病。尽管取得了科学进步并开发了更有效的治疗方法，JMML仍然是一种致命疾病：5年生存率约为50％。在这里，我们报道了最近的研究，这些研究导致人们对JMML涉及的遗传和分子机制有了更好的了解。