Trisomy 12 in chronic lymphocytic leukemia: an interphase cytogenetic study
AP Losada, M Wessman, M Tiainen, AH Hopman, HF Willard, F Sole, MR Caballin, S Woessner and S Knuutila
Department of Medical Genetics, University of Helsinki, Finland.
Interphase cytogenetics by means of in situ hybridization with the
chromosome 12-specific biotinylated alpha satellite DNA probe pSP 12-1 was
used for the study of trisomy 12, the most common chromosomal abnormality
in chronic lymphocytic leukemia. In situ hybridization was performed on
methanol/acetic acid fixed cells of conventional cytogenetic preparations
from eight patients and on morphologically and immunologically classified
cells of cytospin preparations from seven patients. The results show that
trisomy 12 is more common than assumed on the basis of karyotype analysis
of metaphase chromosomes: 2 of 13 patients with a normal karyotype in
G-banding analysis were shown to have trisomy 12 by interphase
cytogenetics. Immunophenotyping of the cells of one patient showed that the
trisomy was restricted to cells with Ig light chain clonality. For the
evaluation of the prognostic, therapeutic, and biologic significance of
trisomy 12, in situ hybridization should be used in parallel with karyotype
analysis because it allows the study of all cell populations of both
interphase and mitotic cells, whether neoplastic or normal.
Volume 78,
Issue 3,
pp. 775-779,
08/01/1991
Copyright © 1991 by The American Society of Hematology
