Download Leukaemia Section t(14;21)(q11;q22) Atlas of Genetics and Cytogenetics in Oncology and Haematology

Atlas of Genetics and Cytogenetics
in Oncology and Haematology
OPEN ACCESS JOURNAL AT INIST-CNRS
Leukaemia Section
Short Communication
t(14;21)(q11;q22)
Jacques Boyer
Laboratoire d'Hématologie, CH du MANS, France (JB)
Published in Atlas Database: November 2004
Online updated version : http://AtlasGeneticsOncology.org/Anomalies/t1421q11q22ID1180.html
DOI: 10.4267/2042/38155
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 2.0 France Licence.
© 2005 Atlas of Genetics and Cytogenetics in Oncology and Haematology
Note
Alias OLIG2.
DNA/RNA
This gene maps within a 9 to 12 Mb region of
chromosome 21q22.
Protein
This gene was shown to possess a helix-loop-helix
(bHLH) motif witch inhibits the E2A function in
transfection assays. E2A is required for normal T-cell
differentiation.
Clinics and pathology
Disease
T-cell Acute lymphoblastic leukemia (T-ALL)
Epidemiology
Rare.
Clinics
One case reported: The patient was a 7-years-old
female with high white blood count with lymphoblasts
positive for T-cell antigens; cerebrospinal fluid
negative for malignant cells; superior mediastinal mass.
Result of the chromosomal
anomaly
Prognosis
The patient attained a complete remission with standard
chemotherapy but relapsed and died after 4 months of
therapy.
Hybrid gene
Note
Translocation of the BHLHB1 gene 130kb upstream of
the TCRA enhancer. This translocation activates the
BHLHB1 gene and produces high levels of BHLHB1
mRNA. Expression of HLHB1 inhibits E2A-mediated
transcription activation in vitro.
Cytogenetics
Cytogenetics morphological
The t(14;21)(q11.2;q22) was accompanied with
del(6)(q21). Cryptic t(14;21) translocation cases may
exist.
Fusion protein
Note
No fusion protein.
Oncogenesis
Several helix-loop-helix (HLH) proteins are proposed
to function as transcriptionnal regulatory factors based
on their ability to bind in vitro the E-box motif of
transcriptional enhancers.
The observation that ectopic BHLHB1 expression can
inhibit E2A activity suggests that BHLHB1 exerts its
leukemogenic effects through a functional inhibition of
E2A.
Genes involved and proteins
TCRA
Location
14q11.2
Protein
T cell receptor.
BHLHB1
Location
21q22
Atlas Genet Cytogenet Oncol Haematol. 2005; 9(1)
26
t(14;21)(q11;q22)
Boyer J
References
development and to rapid development of T-cell lymphomas.
Mol Cell Biol. 1997 Aug;17(8):4782-91
Whitlock JA, Raimondi SC, Harbott J, Morris SW, McCurley
TL, Hansen-Hagge TE, Ludwig WD, Weimann G, Bartram CR.
t(5;14)(q33-34;q11), a new recurring cytogenetic abnormality in
childhood acute leukemia. Leukemia. 1994 Sep;8(9):1539-43
Wang J, Jani-Sait SN, Escalon EA, Carroll AJ, de Jong PJ,
Kirsch IR, Aplan PD. The t(14;21)(q11.2;q22) chromosomal
translocation associated with T-cell acute lymphoblastic
leukemia activates the BHLHB1 gene. Proc Natl Acad Sci U S
A. 2000 Mar 28;97(7):3497-502
Cytogenetic abnormalities in adult acute lymphoblastic
leukemia: correlations with hematologic findings outcome. A
Collaborative Study of the Group Français de Cytogénétique
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This article should be referenced as such:
Boyer J. t(14 ;21)(q11;q22). Atlas Genet Cytogenet Oncol
Haematol. 2005; 9(1):26-27.
Bain G, Engel I, Robanus Maandag EC, te Riele HP, Voland
JR, Sharp LL, Chun J, Huey B, Pinkel D, Murre C. E2A
deficiency leads to abnormalities in alphabeta T-cell
Atlas Genet Cytogenet Oncol Haematol. 2005; 9(1)
27