title: Trisomy 21 in neoplastic cells.
abstract: 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%. Trisomy 21 has never been reported as the sole anomaly in a solid tumor. The cytogenetic literature contains information on 62 patients with constitutional trisomy 21 and a malignant disorder in which the tumor cells have been analyzed by banding techniques. Thirty-four of the 62 patients had AML, 16 had ALL, and 2 had acute undifferentiated leukemia. The 52 leukemic Down syndrome (DS) cases account for 1.4% of the total acute leukemias, an overrepresentation that parallels the generally increased risk of leukemia development in DS. Sixty-three percent of the ALL patients and 79% of those with AML had additional changes superimposed on constitutional trisomy 21. These included several of the characteristic primary leukemia-associated aberrations: 5q-, 7q-, +8, and t(8;21) in AML, and t(1;19), t(4;11), 6q-, and 14q + in ALL. Thus, it seems that the pattern of acquired karyotypic changes is similar in patients with DS and in individuals with a normal constitutional karyotype.
authors: Department of Clinical Genetics, University of Lund, Sweden.
authors: F
authors: F
authors: Mitelman
authors: S
authors: S
authors: Heim
authors: N
authors: N
authors: Mandahl
mesh_terms: D002869:Chromosome Aberrations; D004314:Down Syndrome / Q000150:complications / Q000235:genetics*; D006801:Humans; D007621:Karyotyping; D007938:Leukemia / Q000150:complications / Q000235:genetics*; D008223:Lymphoma / Q000150:complications / Q000235:genetics*; D008232:Lymphoproliferative Disorders / Q000150:complications / Q000235:genetics; D009190:Myelodysplastic Syndromes / Q000150:complications / Q000235:genetics; D009196:Myeloproliferative Disorders / Q000150:complications / Q000235:genetics; D009369:Neoplasms / Q000150:complications / Q000235:genetics*