Abstract：
Transient abnormal myelopoiesis (TAM) in neonates with Down syndrome is a distinct form of leukemia or preleukemia that mirrors the hematological features of acute megakaryoblastic leukemia. However, it typically resolves spontaneously in the early stages. TAM originates from fetal liver (FL) hematopoietic precursor cells and emerges due to somatic mutations in GATA1 in utero. In TAM, progenitor cells proliferate and differentiate into mature megakaryocytes and granulocytes. This process occurs both in vitro, aided by hematopoietic growth factors (HGFs) produced in the FL, and in vivo, particularly in specific anatomical sites like the FL and blood vessels. The FL\'s hematopoietic microenvironment plays a crucial role in TAM\'s pathogenesis and may contribute to its spontaneous regression. This review presents an overview of current knowledge regarding the unique features of TAM in relation to the FL hematopoietic microenvironment, focusing on the functions of HGFs and the pathological features of TAM.
摘要：
患有唐氏综合征的新生儿的暂时性异常骨髓生成（TAM）是白血病或白血病前期的一种独特形式，反映了急性巨核细胞白血病的血液学特征。然而,它通常在早期自发解决。TAM起源于胎儿肝脏（FL）造血前体细胞，并由于子宫内GATA1的体细胞突变而出现。在TAM,祖细胞增殖并分化为成熟的巨核细胞和粒细胞。这个过程既发生在体外，在FL产生的造血生长因子(HGF)的帮助下，在体内，特别是在特定的解剖部位，如FL和血管。FL的造血微环境在TAM的发病机制中起着至关重要的作用，并可能有助于其自发消退。这篇综述概述了有关TAM与FL造血微环境相关的独特特征的当前知识，重点介绍HGFs的功能和TAM的病理特征。
