13q deletions in B-cell lymphoproliferative disorders: frequent association with translocation.

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13q deletions in B-cell lymphoproliferative disorders: frequent association with

translocation.

S Struski, C Helias, C Gervais, B Audhuy, A Zamfir, R Herbrecht, and M Lessard

Cancer Genet Cytogenet, April 15, 2007; 174(2): 151-60.

Laboratoire d'Hématologie, Hôpital de Hautepierre, Avenue Molière, 67098

Strasbourg, France.

The 13q14 deletion is the most frequent abnormality in chronic lymphocytic

leukemias/small lymphocytic lymphomas, and this early rearrangement is observed

from the start of the disease. The systematic use of a panel of interphase

fluorescence in situ hybridization (FISH) may not reveal some probes (targeting

chromosomes 11q, 13q, 17p, and chromosome 12) structural abnormalities. In this

series, we analyzed metaphases by conventional cytogenetics, followed by

interphase and metaphase fluorescence in situ hybridization. We were able to

observe 17 cases of 13q translocations with deletions in eight of them. Three

distinct regions were involved by translocations in association with or without

deletions: a region centromeric to RB1 (13q11 approximately 13), a zone

telomeric to D13D25 (13q21 approximately 31), and a 13q14 region deliniated by

RB1 and D13S25. In this area, the deletion was variable: RB1 alone (one case),

D13S319 approximately D13S25 (five cases), and from RB1 to D13S25 (two cases).

The very high frequency of 13q14 loss suggests that these deletions are of

pathogenetic importance, but, the importance of the translocations remains to be

determined.

PMID: 17452258