Pediatric Myelodysplastic Syndrome: Symptoms, Diagnosis, and Treatment Options

Myelodysplastic syndrome (MDS) in children is a rare and complex blood disorder characterized by the bone marrow's inability to produce healthy, mature blood cells. Unlike adult MDS, pediatric cases often present with unique clinical features and require specialized diagnostic and therapeutic approaches. Early recognition of symptoms can significantly influence treatment outcomes and long-term prognosis.

Common Clinical Manifestations of Pediatric MDS

Children affected by myelodysplastic syndrome typically exhibit signs related to ineffective hematopoiesis—meaning the body struggles to generate functional red blood cells, white blood cells, and platelets. The most prevalent symptom is chronic anemia, which may lead to fatigue, pallor, shortness of breath, and reduced physical stamina. In many cases, anemia is persistent and does not respond well to conventional treatments such as iron supplementation or vitamin therapy.

In addition to anemia, patients may experience bleeding tendencies due to low platelet counts (thrombocytopenia). This can manifest as easy bruising, petechiae (small red or purple spots on the skin), nosebleeds, or prolonged bleeding from minor injuries. Recurrent infections are also common, resulting from neutropenia, or a deficiency in functional white blood cells, particularly granulocytes, which play a key role in fighting bacterial and fungal pathogens.

Some children may also present with hepatosplenomegaly (enlarged liver and spleen) or generalized lymphadenopathy (swollen lymph nodes). While these findings are not universal, their presence can prompt further investigation into underlying hematologic disorders.

Blood and Bone Marrow Findings

Peripheral Blood Abnormalities

Complete blood count (CBC) analysis typically reveals cytopenias—low levels in one, two, or all three major blood cell lines: hemoglobin (anemia), neutrophils (neutropenia), and platelets (thrombocytopenia). This pancytopenia or multilineage dysplasia is a hallmark of MDS and helps differentiate it from other causes of low blood counts in children, such as nutritional deficiencies or transient viral suppression.

Peripheral blood smears may show abnormal cell morphology, including hypogranular neutrophils, pseudo-Pelger-Huët anomalies, or fragmented red blood cells, providing additional clues to the presence of dysplastic hematopoiesis.

Bone Marrow Examination

A definitive diagnosis requires a bone marrow aspiration and biopsy. In pediatric MDS, the marrow is often hypercellular, meaning it is packed with developing blood cells, yet fails to release adequate numbers of mature, functional cells into circulation. This phenomenon, known as ineffective hematopoiesis, is accompanied by morphological evidence of dysplasia in at least one cell lineage—erythroid, myeloid, or megakaryocytic.

Dysplastic changes may include megaloblastoid erythropoiesis, abnormal nuclear segmentation in granulocyte precursors, or micromegakaryocytes with single nuclei. Cytogenetic testing and molecular profiling are essential to identify chromosomal abnormalities such as monosomy 7 or mutations in genes like SAMD9, SAMD9L, or GATA2, which are more frequently associated with childhood MDS than adult forms.

Risk of Leukemic Transformation

One of the most concerning aspects of pediatric MDS is its potential to progress to acute myeloid leukemia (AML). Children with high-risk subtypes, especially those with excess blasts or specific genetic mutations, face a significantly elevated risk of transformation. Once AML develops, aggressive chemotherapy becomes necessary, although response rates vary depending on age, genetic profile, and overall health status.

Because of this inherent instability in the hematopoietic system, early intervention is crucial. Close monitoring through regular blood tests and bone marrow evaluations allows clinicians to detect progression at an early stage and initiate timely treatment.

Treatment Approaches and Long-Term Management

Managing pediatric myelodysplastic syndrome is challenging due to its refractory nature. Conventional supportive therapies such as blood transfusions and antimicrobial prophylaxis help manage symptoms but do not alter the disease course. Growth factor therapies like erythropoietin or G-CSF have limited efficacy in children compared to adults.

This procedure involves replacing the child's defective bone marrow with healthy stem cells from a matched donor, ideally a sibling or unrelated HLA-compatible individual. Success rates are higher when transplantation is performed before the onset of AML and in younger patients with fewer comorbidities.

Despite advances in transplant techniques and conditioning regimens, challenges remain—including graft-versus-host disease (GVHD), infection risks, and long-term side effects. Therefore, comprehensive pre-transplant evaluation and post-transplant care are vital components of treatment planning.

In recent years, research has focused on targeted therapies and immunomodulatory agents for patients who are not immediate candidates for transplantation. Clinical trials exploring novel drugs and gene-editing technologies offer hope for future breakthroughs in managing this rare but serious condition.