title: An apparent tandem quadruplication of chromosome 21 in a case of childhood acute lymphoblastic leukemia.
abstract: A case of childhood ALL is presented in which the leukemic clone had both normal chromosomes #21 replaced by a single marker chromosome that contained four copies of chromosome #21 arranged in tandem. This unique report further emphasizes the role played by multiple copies of chromosome #21 in acute leukemia. The observation of one cell in which the marker appeared to consist of only three copies of chromosome #21 arranged in tandem raises the possibility that the marker chromosome arose as a result of a stepwise amplification process.
authors.forename: I D
authors.initials: ID
authors.lastname: Dubé
authors.forename: H
authors.initials: H
authors.lastname: el-Solh
mesh_terms: D000293:Adolescent; D002869:Chromosome Aberrations; D002891:Chromosomes, Human, Pair 21; D005260:Female; D005819:Genetic Markers; D006801:Humans; D007621:Karyotyping; D007945:Leukemia, Lymphoid / Q000235:genetics*
chemical_list: D005819:Genetic Markers