Trisomy 21 in transient myeloproliferative disorder

Area of Science:

• Pediatric Hematology
• Clinical Genetics
• Neonatology

Background:

• Transient leukemia is a rare, often self-resolving hematological condition observed in newborns.
• Phenotypically normal infants developing leukemia presents a diagnostic challenge.
• The association between transient leukemia and specific chromosomal abnormalities, like trisomy 21, requires further investigation.

Observation:

• A newborn presented with fever and tachypnea at 2 days old, exhibiting a high white blood cell count with abnormal blast cells.
• Chromosome analysis revealed trisomy 21 in spontaneously dividing blood cells and 80% of bone marrow cells.
• Skin fibroblast cultures did not show trisomic cells, suggesting a specific hematological origin.

Findings:

• The infant diagnosed with transient leukemia and trisomy 21 showed a complete resolution of abnormal cells by 6 months of age.
• Blood film normalized, and trisomic cells were no longer detectable, confirming the transient nature of the leukemia.
• The absence of trisomic cells in non-hematopoietic tissues highlights the specific involvement of blood and marrow cells.

Implications:

• This case underscores the importance of considering transient leukemia in newborns, even those with apparent normal phenotypes.
• The spontaneous resolution of leukemia in this trisomy 21 infant suggests unique biological mechanisms.
• Further research into transient leukemia in infants with chromosomal abnormalities can inform diagnostic and prognostic strategies.