title: Frequent deletions at 12q14.3 chromosomal locus in adult acute lymphoblastic leukemia.
abstract: Cytogenetic abnormalities at the 12q12-q14 chromosomal locus are rarely detected in acute lymphoblastic leukemia (ALL). To examine submicroscopic deletions at this locus, we analyzed 78 adult precursor B- and T-cell ALL cases [27 with Philadelphia chromosome (Ph)-negative B-cell ALL, 20 with Ph-negative B-cell ALL with expression of one or two myeloid markers, 18 with Ph-positive B-cell ALL, and 13 with T-cell ALL] using a panel of 13 microsatellite (MST) markers that span the 12q12-q14.3 region. The status of MST markers was evaluated by use of polymerase chain reaction performed with fluorescence-labeled primers and automated fragment analysis. The MST marker analyses showed submicroscopic deletions at the 12q14.3 locus in 20 of the 78 ALL cases (26%). The frequency of deletions was highest in Ph-negative B-cell ALL (13 of 27, 48%) compared with that in Ph-negative B-cell ALL with expression of myeloid markers (4 of 20, 20%), Ph-positive B-cell ALL (2 of 18, 11%), and T-cell ALL (1 of 13, 8%). Deletion frequencies of MST markers along the 12q12-q14.3 locus suggest that the targeted gene of deletion is located within a 170-kb region bordered by the markers D12S1504 (approximately 65 kb upstream of HMGA2) and D12S1509 (in intron 3 of HMGA2) at the 12q14.3 locus. These submicroscopic deletions at the 12q14.3 locus may play a role in the pathogenesis of ALL, particularly in Ph-negative precursor B-cell ALL.
authors.affiliation: Department of Hematopathology, Division of Pathology and Laboratory Medicine, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA.
authors.forename: Hemantkumar S
authors.initials: HS
authors.lastname: Patel
authors.forename: Hagop M
authors.initials: HM
authors.lastname: Kantarjian
authors.forename: Carlos E
authors.initials: CE
authors.lastname: Bueso-Ramos
authors.forename: L Jeffrey
authors.initials: LJ
authors.lastname: Medeiros
authors.forename: Mohammad A
authors.initials: MA
authors.lastname: Haidar
mesh_terms: D000328:Adult; D002869:Chromosome Aberrations; D002872:Chromosome Deletion; D002874:Chromosome Mapping; D002882:Chromosomes, Human, Pair 13 / Q000235:genetics*; D005819:Genetic Markers; D006801:Humans; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000235:genetics*; D019656:Loss of Heterozygosity; D015183:Restriction Mapping
chemical_list: D005819:Genetic Markers