Acute promyelocytic leukemia with apparently normal karyotype: molecular findings and response to all-trans retinoic acid.
Acute promyelocytic leukemia (APL) is specifically associated with a reciprocal translocation, t(15; 17)(q22; q21), leading to the formation of a fusion of the retinoic acid receptor-alpha (RARA) gene and the promyelocytic leukemia (PML) gene. However, there are several reports describing APL cases lacking the t(15; 17). Many such cases are those bearing variant translocations involving chromosomes 15 or 17, and those with no chromosomal aberrations have rarely been reported. We have studied a patient with APL showing an apparently normal karyotype which was confirmed by spectral karyotyping (SKY). A submicroscopic PML-RARA fusion was identified by reverse transcriptase-polymerase chain reaction (RT-PCR) and fluorescent in situ hybridization (FISH). All-trans retinoic acid (ATRA) was effective as the initial therapy for remission induction and as the reinduction therapy after a relapse. The present study shows the key role of the fusion of PML-RARA in the responsiveness to ATRA as well as in the leukemogenesis of APL.
Kohno
A
A
First Department of Internal Medicine, Nagoya University School of Medicine, Nagoya, Japan. akohno@wd5.so-net.ne.jp
Tsuzuki
S
S
Kasai
M
M
Miyamura
K
K
Emi
N
N
Tanimoto
M
M
Saito
H
H
D000970:Antineoplastic Agents / Q000008:administration & dosage; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D015473:Leukemia, Promyelocytic, Acute / Q000188:drug therapy / Q000209:etiology / Q000235:genetics*; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000032:analysis / Q000235:genetics; D015514:Oncogene Proteins, Fusion / Q000032:analysis / Q000235:genetics; D012074:Remission Induction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014212:Tretinoin / Q000008:administration & dosage
D000970:Antineoplastic Agents; D009363:Neoplasm Proteins; D015514:Oncogene Proteins, Fusion; C093476:promyelocytic leukemia-retinoic acid receptor alpha fusion oncoprotein; D014212:Tretinoin