E2A/HLF fusion gene in an acute lymphoblastic leukemia patient with disseminated intravascular coagulation and a normal karyotype.
BACKGROUND
Disseminated intravascular coagulation (DIC) is a rare event in acute lymphoblastic leukemia (ALL). However, it has been described in a few cases of pre-B ALL with translocation t(17;19)(q22;p13) which results in the fusion of E2A gene with sequences of HLF gene. Here, we report a case of pre-B ALL with DIC and an apparently normal karyotype by R banding.


METHODS
Fluorescent in situ hybridization (FISH) studies were performed on bone marrow cells from the patient at presentation and after three months of therapy. RT-PCR was used to detect the E2A-HLF transcript. The type of rearrangement was characterized by sequencing.


RESULTS
The t(17;19)(q22;p13) was detected by FISH analysis. The fusion E2A-HLF was amplified by RT-PCR and sequenced, giving a type I rearrangement with a long insertion (146 nucleotides) between E2A exon 13 and HLF exon 4.


CONCLUSIONS
While translocation t(17;19) is undetectable by R-banding technique, it can be detected with FISH and amplified with RT-PCR. Therefore, systematic molecular investigations should be conducted for all patients with pre-B ALL associated with DIC, in order to appreciate the incidence and the prognostic value of this rare abnormality.
Dahéron
Laurence
L
Laboratoire d'Hématologie (CNRS FRE 2224), Poitiers University Hospital, France.
Brizard
Françoise
F
Millot
Frédéric
F
Cividin
Marie
M
Lacotte
Laurence
L
Guilhot
François
F
Brizard
André
A
D002648:Child; D002886:Chromosomes, Human, Pair 17; D002888:Chromosomes, Human, Pair 19; D004268:DNA-Binding Proteins / Q000235:genetics*; D004211:Disseminated Intravascular Coagulation / Q000209:etiology / Q000235:genetics*; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D007621:Karyotyping; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000150:complications / Q000235:genetics; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000150:complications* / Q000235:genetics; D014157:Transcription Factors; D014178:Translocation, Genetic
D004268:DNA-Binding Proteins; C076554:E2a-Hlf fusion protein, human; D015514:Oncogene Proteins, Fusion; D014157:Transcription Factors