UNIVERSITY OF MALTA
LIFE SCIENCE RESEARCH SEMINARS
Web: http://events.um.edu.mt/scisem/
Email: scisem@um.edu.mt
Abstract form
Title: Characterization of chromosomal abnormalities involving 2p
translocations in B cell precursor acute lymphoblastic leukaemia
(BCP-ALL)
Presenter: Roberto Avellino
Contact address:
Tel: 79068404
Fax:
Email: robert.a.avellino@gov.mt
Presentation date: 9th November 2009
Abstract
Chromosomal abnormalities involving the immunoglobulin loci, IGH@, IGK@ or IGL@
play an important role in the pathogenesis of B cell malignancies. These abnormalities are
frequently reported in mature B cell lymphomas, with recent studies showing recurrent
involvement of IGH@ in B cell precursor acute lymphoblastic leukaemia (BCP-ALL). These
findings prompted interest into studying the involvement of the IGK@ locus, at chromosome
2p11, in a subset of BCP-ALL patients with 2p translocations. In this project, a cohort of 39
patients (median: age= 8years; white cell count= 13x109/L) was screened by fluorescence in
situ hybridization (FISH). IGK@ was involved in four cases detected by metaphase (cases
n=3) and interphase (cases n=1) FISH, with breakpoints occurring within the IGK@ locus.
Other translocation with breakpoints at 2p, either telomeric (cases n=8) or centromeric (cases
n=5) of the IGK@ locus, were detected by metaphase FISH and showed no involvement of
IGK@. Partner chromosomes were confirmed by whole chromosome paints and the
corresponding genes were further investigated by FISH mapping in 2 cases. A potential
candidate gene, ELAVL2, at 9p21 was mapped and analyzed for expression by quantitative
real time polymerase chain reaction. Further FISH investigations were performed in this
cohort to study the possible contribution of other abnormalities in two other genes, CRLF2
(involvement n=1) and CDKN2A (biallelic deletions n=6; monoallelic deletions n=9). The
biological importance of 2p translocations is to be determined in BCP-ALL, along with the
prognostic significance of these translocations in relation to therapeutic response and disease
outcome of these patients.