Three distinct subgroups of hypodiploidy in acute lymphoblastic leukaemia.
This study of children and adults with acute lymphoblastic leukaemia (ALL) is the largest series of patients with hypodiploidy (<46 chromosomes) yet reported. The incidence of 5% was independent of age. Patients were subdivided by the number of chromosomes; near-haploidy (23-29 chromosomes), low hypodiploidy (33-39 chromosomes) and high hypodiploidy (42-45 chromosomes). The near-haploid and low hypodiploid groups were characterized by their chromosomal gains and a doubled hyperdiploid population. Structural abnormalities were more frequent in the low hypodiploid group. Near-haploidy was restricted to children of median age 7 years (range 2-15) whereas low hypodiploidy occurred in an older group of median age 15 years (range 9-54). Patients with 42-45 chromosomes were characterized by complex karyotypes involving chromosomes 7, 9 and 12. The features shared by the few patients with 42-44 chromosomes and the large number with 45 justified their inclusion in the same group. Survival analysis showed a poor outcome for the near-haploid and low hypodiploid groups compared to those with 42-45 chromosomes. Thus cytogenetics, or at least a clear definition of the modal chromosome number, is essential at diagnosis in order to stratify patients with hypodiploidy into the appropriate risk group for treatment.
Harrison
Christine J
CJ
Leukaemia Research Fund Cytogenetics Group, Cancer Sciences Division, University of Southampton, Southampton, UK. harrison@soton.ac.uk
Moorman
Anthony V
AV
Broadfield
Zoë J
ZJ
Cheung
Kan L
KL
Harris
Rachel L
RL
Reza Jalali
G
G
Robinson
Hazel M
HM
Barber
Kerry E
KE
Richards
Sue M
SM
Mitchell
Christopher D
CD
Eden
Tim O B
TO
Hann
Ian M
IM
Hill
Frank G H
FG
Kinsey
Sally E
SE
Gibson
Brenda E S
BE
Lilleyman
John
J
Vora
Ajay
A
Goldstone
Anthony H
AH
Franklin
Ian M
IM
Durrant
Jill
J
Martineau
Mary
M
D000293:Adolescent; D000328:Adult; D000782:Aneuploidy; D002648:Child; D002877:Chromosomes, Human / Q000235:genetics*; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007621:Karyotyping; D008297:Male; D008875:Middle Aged; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics*; D011379:Prognosis; D016019:Survival Analysis