dic(9;20): a new recurrent chromosome abnormality in adult acute lymphoblastic leukemia.
Loss of chromosome 20 and rearrangement of the short arm of chromosome 9 were identified by banding analysis of three adult patients with acute lymphoblastic leukemia (ALL). The G-banding pattern suggested an identical deletion of 9p, but, also, an unbalanced translocation with chromosome 20 was taken into consideration. Dual-color chromosome painting with probes for chromosomes 9 and 20 revealed the presence of material from chromosome 20 at the short arm of the abnormal chromosome 9 in all three cases. Centromeric alpha-satellite DNA of both chromosome 9 and chromosome 20 was demonstrated by fluorescence in situ hybridization and indicated the presence of a dicentric chromosome. The hybridization of a YAC clone of the short arm of chromosome 20 proved that the dicentric chromosome contained the short arm of chromosome 20, which had been suspected from the G-banding pattern. Thus, the rearrangement was interpreted as dic(9;20)(p11;q11.?1). Because this was the sole chromosome abnormality in two patients, dic(9;20) may be a primary chromosome aberration in ALL. In one case, a 9q+ chromosome derived from a Philadelphia (Ph) translocation was involved in the formation of the dicentric chromosome. Immunophenotyping revealed CD10+ B-cell precursor ALL in all three cases. Whereas the two patients in whom dic(9;20) was the sole cytogenetically detectable change are in continuous complete remission for 10 and 45 months, respectively, the Ph+ patient relapsed with leukemia and died 8 months after diagnosis.
Rieder
H
H
Institut für Humangenetik, Medizinische Universität, Lübeck, Federal Republic of Germany.
Schnittger
S
S
Bodenstein
H
H
Schwonzen
M
M
Wörmann
B
B
Berkovic
D
D
Ludwig
W D
WD
Hoelzer
D
D
Fonatsch
C
C
D000328:Adult; D002503:Centromere; D002872:Chromosome Deletion; D002880:Chromosomes, Human, Pair 11; D002890:Chromosomes, Human, Pair 20; D002899:Chromosomes, Human, Pair 9; D004276:DNA, Satellite / Q000032:analysis; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008297:Male; D008875:Middle Aged; D010677:Philadelphia Chromosome; D016133:Polymerase Chain Reaction; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics*; D014178:Translocation, Genetic
D004276:DNA, Satellite