Unique cytogenetic findings confirmed by FISH in a rare case of infant MDS with major prognostic implications
- Univ. of South Florida, Tampa, FL (United States); and others
An extremely rare finding in the young, the myelodysplastic syndrome (MDS) refractory anemia with excess blasts (RAEB), is distinguished by blood cytopenia, trilineage dyspoiesis and an increase in peripheral and bone marrow blasts. A 3-year-old male presented with arm pain of one week duration followed by progressive bruising, high fever and severe headaches. Bone marrow pathology revealed dysmyelopoietic granulocytic hyperplasia, marked reduction in megakaryocytes and increased blastosis suggestive of RAEB. Peripheral blood smear confirmed leukoerythroblastic anemia, reticulocytopenia and thyrombocytopenia. Cytogenetic bone marrow evaluation showed the majority of cells with ring (11), monosomies No. 17 and No. 20 and a derivative No. 12 chromosome. Due to the structural complexity and diagnostic and prognostic implications of accurate interpretation, analysis was confirmed using FISH COATASOME probes No. 11, No. 12 and No. 20 (Oncor, Inc.). The rearranged chromosome comprised chromosomes 12 and 20. Breakpoints in No. 12 were at p13 and q24.3. The breakpoint in chromosome 20 at q11.2 resulted in attachment of the distal 20q11.2 fragment to 12q and the centromere and p arm to 12p. C-banding confirmed two centromeres. Progression to ANLL is observed in 15-30% of patients with MDS. Distinction between RAEB and ANLL challenges diagnosis and patient management. Clonal chromosomal abnormalities due to RAEB and nonrandom ANLL changes also show considerable overlap, emphasizing their basic pathobiological similarity. However, r(11) has been described in ANLL and although the structurally rearranged No. 12 is believed to be a unique finding, the breakpoints were considered diagnostically significant. The presence of unusual cytogenetic findings may herald progression of MDS to acute leukemia before morphological classification is evident, emphasing the importance of clarifying structural abnormalities that may provide powerful evidence for clinical management.
- OSTI ID:
- 134554
- Report Number(s):
- CONF-941009-; ISSN 0002-9297; TRN: 95:005313-1288
- Journal Information:
- American Journal of Human Genetics, Vol. 55, Issue Suppl.3; Conference: 44. annual meeting of the American Society of Human Genetics, Montreal (Canada), 18-22 Oct 1994; Other Information: PBD: Sep 1994
- Country of Publication:
- United States
- Language:
- English
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