Transient abnormal myelopoiesis in a phenotypically normal newborn with polyclonal trisomy 21.
We report a rare case of transient abnormal myelopoiesis (TAM) in a phenotypically normal neonate. The presence of a palpable hepatomegaly prompted in-depth laboratory tests, which revealed the presence of severe hyperleukocytosis, with blast cells present in a peripheral blood smear. Although no signs of Down syndrome were present, we suspected TAM. Further analysis identified a mutation in GATA1 along with the unique finding of two different trisomic cell lines, detected upon karyotyping; one with trisomy 21 only, and one with trisomies 21 and 22, which was present in a subpopulation of peripheral blood cells. These genetic abnormalities disappeared by the age of 6 months. The presence of two different trisomic clones may be an evidence of the polyclonal nature of TAM in this patient.
Department of Pediatric Hematology and Oncology, S. Orsola-Malpighi Hospital, University of Bologna, Via Massarenti 11, Building 13, 40138, Bologna, Italy.
Francesco
F
Corazza
Annalisa
A
Astolfi
Virginia
V
Libri
Monica
M
Franzoni
Salvatore
S
Serravalle
Rosina
R
Alessandroni
Fraia
F
Melchionda
Andrea
A
Pession
D002871:Chromosome Banding; D002891:Chromosomes, Human, Pair 21; D004314:Down Syndrome / Q000175:diagnosis* / Q000235:genetics*; D050982:GATA1 Transcription Factor / Q000235:genetics; D006801:Humans; D016130:Immunophenotyping; D007231:Infant, Newborn; D007955:Leukemoid Reaction / Q000175:diagnosis* / Q000235:genetics*; D008297:Male; D009154:Mutation; D010641:Phenotype; D014314:Trisomy
D050982:GATA1 Transcription Factor