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Myeloid Proliferations Associated with Down Syndrome: Clinicopathologic Characteristics of Forty Cases from Five
Tayler A van den Akker1, Yen-Chun Liu2,3, Huifei Liu4
1Department of Pathology, Weill Cornell Medicine, New York, New York, USA.
Insights
Children with Down syndrome (DS) have increased risks of myeloid leukemia associated with DS (ML-DS) and transient abnormal myelopoiesis (TAM). This study identifies key clinical, morphological, and genetic differences to aid in differentiating these conditions.
Area of Science:
- Hematology
- Pediatric Oncology
- Genetics
Background:
- Children with Down syndrome (DS) exhibit a higher incidence of myeloid leukemia associated with DS (ML-DS) and transient abnormal myelopoiesis (TAM).
- TAM, though self-limiting, increases the risk of developing ML-DS later.
- Distinguishing between TAM and ML-DS is clinically crucial but challenging.
Purpose of the Study:
- To identify differentiating criteria between myeloid leukemia associated with DS (ML-DS) and transient abnormal myelopoiesis (TAM) in infants with Down syndrome.
- To compare clinical, pathological, immunophenotypical, and molecular features of ML-DS and TAM.
Main Methods:
- Retrospective review of 28 ML-DS and 12 TAM cases from five US academic institutions.
- Assessment of clinical presentation, morphology, immunophenotype, and molecular genetics.
Main Results:
- Younger age and significant anemia/thrombocytopenia were characteristic of TAM and ML-DS, respectively.
- Dyserythropoiesis and non-trisomy 21 structural cytogenetic abnormalities were unique to ML-DS.
- Immunophenotypic profiles, including CD7 and CD56 expression, were indistinguishable between TAM and ML-DS.
Conclusions:
- While TAM and ML-DS share biological similarities, distinct clinical, morphological, and genetic features exist.
- The study provides insights for differential diagnosis and clinical management of these conditions in infants with Down syndrome.
Introduction:
The incidence of myelodysplastic syndrome and acute myeloid leukemia is significantly increased in children with Down syndrome (DS). Within the revised 2016 WHO edition, these entities are jointly classified as myeloid leukemia associated with DS (ML-DS). Additionally, infants with DS may develop transient abnormal myelopoiesis (TAM) which is histomorphologically similar to ML-DS. While TAM is self-limiting, it is associated with an increased risk of subsequently developing ML-DS. Differentiating TAM and ML-DS is challenging but clinically critical.
Methods:
We performed a retrospective review of ML-DS and TAM cases collected from five large academic institutions in the USA. We assessed clinical, pathological, immunophenotypical, and molecular features to identify differentiating criteria.
Results:
Forty cases were identified: 28 ML-DS and 12 TAM. Several features were diagnostically distinct, including younger age in TAM (p < 0.05), as well as presentation with clinically significant anemia and thrombocytopenia in ML-DS (p < 0.001). Dyserythropoiesis was unique to ML-DS, as well as structural cytogenetic abnormalities aside from the constitutional trisomy 21. Immunophenotypic characteristics of TAM and ML-DS were indistinguishable, including the aberrant expression of CD7 and CD56 by the myeloid blasts.
Discussion:
The findings of the study confirm marked biological similarities between TAM and ML-DS. At the same time, several significant clinical, morphological, and genetic differences were observed between TAM and ML-DS. The clinical approach and the differential diagnosis between these entities are discussed in detail.
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