Frequent deletions at 12q14.3 chromosomal locus in adult acute lymphoblastic leukemia

✍ Scribed by Hemantkumar S. Patel; Hagop M. Kantarjian; Carlos E. Bueso-Ramos; L. Jeffrey Medeiros; Mohammad A. Haidar

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 316 KB
• Volume: 42
• Category: Article
• ISSN: 1045-2257
• DOI: 10.1002/gcc.20116

✦ Synopsis

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. © 2004 Wiley‐Liss, Inc.