An unusual cytogenetic rearrangement originating from two different abnormalities in chromosome 6 in a child with acute promyelocytic leukemia.
Acute promyelocytic leukemia (APL) is usually associated with a favorable outcome, but about 10% of patients tend to relapse. The genetic hallmark of APL is a balanced translocation involving chromosomes 15 and 17, and the PML-RARa gene fusion is found in more than 90% of these cases. Other chromosomal abnormalities are commonly found in APL, but their clinical significance has yet to be determined. Here we report a case of childhood APL that was studied by conventional cytogenetics along with molecular cytogenetic techniques. The patient showed a complex karyotype with an unusual cytogenetic rearrangement originating from two different abnormalities in a single chromosome 6. Our case is an exceptional example of a cryptic cytogenetic anomaly in APL and underscores the importance of detailed genetic characterization.
Bone Marrow Unit, Cytogenetics Department, National Cancer Institute, Rio de Janeiro, Brazil.
R R C
RR
Matos
H
H
Mkrtchyan
B A S
BA
Amaral
T
T
Liehr
M T
MT
de Souza
D R
DR
Ney-Garcia
N
N
Santos
T J
TJ
Marques-Salles
R C
RC
Ribeiro
A F
AF
Figueiredo
M L M
ML
Silva
D002648:Child; D002871:Chromosome Banding; D002884:Chromosomes, Human, Pair 15; D002886:Chromosomes, Human, Pair 17; D002896:Chromosomes, Human, Pair 6; D015321:Gene Rearrangement; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D015473:Leukemia, Promyelocytic, Acute / Q000235:genetics*; D008297:Male; D014178:Translocation, Genetic / Q000235:genetics*