Chromosome 8 tetrasomies and pentasomies--a clonal abnormality closely associated with acute monocytic leukaemia.
We report four cases of polysomy 8 (one tetrasomy and three pentasomies) observed in acute monocytic leukemia (FAB M4 and M5). Three of them showed a rearrangement of 11q23 identified by conventional cytogenetic analysis and/or chromosome painting. Our cases as well as a review of the literature, suggest that polysomy 8 is preferentially associated with monocytic differentiation (24/31). These polysomies have been observed in 21 de novo leukemias and in 10 secondary hematological disorders. A 11q23 rearrangement has been detected in 9 out of 32 patients, by conventional cytogenetic techniques in 7 and by FISH in 2. We suggest that these cases should be analysed by FISH and molecular studies in order to detect a rearrangement of MLL/11q23. Monocytic differentiation is often associated with a change of the MLL gene and the polysomy 8 might be a particular clonal evolution secondary to 11q23 abnormality.
Lessard
M
M
Laboratoire de Cytologie & Cytogénétique and Service d'Hématologie CHU, Brest, France. Michel.Lessard@Univ-brest.fr
Herry
A
A
Berthou
C
C
Léglise
M C
MC
Abgrall
J F
JF
Luquet
I
I
Dastugue
N
N
Duchayne
E
E
Rigal-Huguet
F
F
Lafage
M
M
Sainty
D
D
Reiffers
J
J
Bernard
P
P
D000293:Adolescent; D000368:Aged; D002869:Chromosome Aberrations; D002880:Chromosomes, Human, Pair 11; D002898:Chromosomes, Human, Pair 8; D005260:Female; D006801:Humans; D007948:Leukemia, Monocytic, Acute / Q000235:genetics*; D008297:Male; D008875:Middle Aged