Detection of 16 p deletions by FISH in patients with inv(16) or t(16;16) and acute myeloid leukemia (AML).
Deletions of sequences centromeric to the p-arm breakpoint have been described in a subset of patients with inv(16) and acute myeloid leukemia (AML) and reported to be associated with a relatively good prognosis. We have investigated 16 p deletions in a cohort of 15 patients with AML and inv(16) or t(16;16) and compared non-deletion and deletion patients in terms of clinical course. Patients were studied by fluorescence in situ hybridization (FISH) using cosmid zit14 as a probe to detect the presence of 16 p deletions in metaphase chromosomes of leukemic cells. While seven patients (47%) revealed no evidence of a deletion, five patients (33%) presented 16 p deletions, thus bringing further support to the relatively frequent occurrence of this event in inv(16) patients. Remarkably, two patients with inv(16) and one patient with t(16;16) showed a mosaicism of deletion and non-deletion metaphases suggesting the presence of two distinct leukemic cell populations. Results let us assume that 16 p deletions are not restricted to inv(16) and may occur subsequently to inv(16) or t(16;16). The presence of a 16 p deletion in a case of inv(16) associated with CBFB-MYH11 transcript type E indicates that deletions are not limited to CBFB-MYH11 transcript type A rearrangements. Survival of deletion patients was compared with that of non-deletion and mosaic ones. No significant differences were observed. The advantage of FISH for enumerative and quantitative assessment of submicroscopic rearrangements of clinical significance is further emphasized.
Martinet
D
D
Division Autonome de Génétique Médicale, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland.
Mühlematter
D
D
Leeman
M
M
Parlier
V
V
Hess
U
U
Gmür
J
J
Jotterand
M
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D002872:Chromosome Deletion; D007446:Chromosome Inversion; D002885:Chromosomes, Human, Pair 16; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D015470:Leukemia, Myeloid, Acute / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D014178:Translocation, Genetic