Cai Junpeng, Zhou Xiaomin, Zhou Yu, Pi Guanghuan
Department of Pediatrics, Affiliated Hospital of North Sichuan Medical College, Nanchong 637000, China.
Department of Pediatrics, Sichuan Provincial Maternity and Child Health Care Hospital, Chengdu 610000, China.
Mol Genet Metab Rep. 2024 Dec 20;42:101177. doi: 10.1016/j.ymgmr.2024.101177. eCollection 2025 Mar.
Transient abnormal myelopoiesis (TAM) is a congenital leukemia specific to neonates with Down syndrome (DS) or trisomy 21. However, rare cases of TAM can also occur with acquired trisomy 21 mutations or mosaic trisomy 21, leading to potential misdiagnosis due to the absence of the DS phenotypes.
We present a case of TAM in a neonate without typical DS phenotypic features. We documented medical records from hospitalizations and a one-year follow-up period. Additionally, through a literature review, we summarized the clinical phenotype and genotypic characteristics observed in similar neonates.
Despite the lack of typical DS phenotype the neonate was diagnosed with TAM upon detection of trisomy 21 and the GATA1 gene mutation, the condition resolved spontaneously without requiring chemotherapy. We monitored the neonate for a full year, during which no hematologic or developmental abnormalities were observed. Thirteen previous cases of neonates with TAM but without the DS phenotype have been reported. During the onset of TAM, the presence of trisomy 21 can be detected in peripheral blood cells or bone marrow cells, but some patients may not show evidence of trisomy 21 in fibroblasts. In these patients, trisomy 21 in peripheral blood cells or bone marrow cells may gradually decrease and even disappear as TAM improves. All patients experienced self-limiting remission with a favorable prognosis, although one case progressed to myeloid leukemia associated with DS by age two.
A negative obstetrical diagnosis and the absence of clinical DS phenotype should not preclude the consideration of TAM in neonates, especially when trisomy 21 mutations are detected.
短暂性异常髓系造血（TAM）是一种特定于唐氏综合征（DS）或21三体新生儿的先天性白血病。然而，罕见的TAM病例也可发生于获得性21三体突变或21三体嵌合体，由于缺乏DS表型，可能导致误诊。
我们报告一例无典型DS表型特征的新生儿TAM病例。我们记录了住院期间和一年随访期的病历。此外，通过文献综述，我们总结了在类似新生儿中观察到的临床表型和基因型特征。
尽管缺乏典型的DS表型，但该新生儿在检测到21三体和GATA1基因突变后被诊断为TAM，病情自发缓解，无需化疗。我们对该新生儿进行了一整年的监测，在此期间未观察到血液学或发育异常。此前已报道过13例无DS表型的新生儿TAM病例。在TAM发病时，外周血细胞或骨髓细胞中可检测到21三体，但部分患者的成纤维细胞中可能未显示21三体证据。在这些患者中，随着TAM病情改善，外周血细胞或骨髓细胞中的21三体可能逐渐减少甚至消失。所有患者均经历自限性缓解，预后良好，尽管有1例在2岁时进展为与DS相关的髓系白血病。
产科诊断阴性且缺乏临床DS表型不应排除对新生儿TAM的考虑，尤其是在检测到21三体突变时。
