tumoral trisomy 21
Trisomy 21 as an acquired clonal chromosome change has been described in 642 of the 10,625 human neoplasms with chromosome aberrations known from the cytogenetic literature. A total of 590 of the 642 cases (92%) are hematologic disorders and malignant lymphomas.
The incidence of trisomy 21 is similar (4.1%-6.7%) in acute myeloid leukemia (AML), chronic myeloid leukemia, myeloproliferative disorders, myelodysplastic syndromes, chronic lymphoproliferative disorders, and malignant lymphomas; it is substantially higher (14.8%) in acute lymphocytic leukemia (ALL).
In most cases, the extra chromosome 21 is present together with other numerical and/or structural changes.
Acquired trisomy 21 is the only karyotypic abnormality in only 0.4%.
References
Watson MS, Carroll AJ, Shuster JJ, Steuber CP, Borowitz MJ, Behm FG, Pullen DJ, Land VJ. Trisomy 21 in childhood acute lymphoblastic leukemia: a Pediatric Oncology Group study (8602). Blood. 1993 Nov 15;82(10):3098-102. PMID: 8219201
Mitelman F, Heim S, Mandahl N. Trisomy 21 in neoplastic cells. Am J Med Genet Suppl. 1990;7:262-6. PMID: 2149959