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Leukaemia Section
Mini Review
der(6)t(1;6)(q21-23;p21)
Adriana Zamecnikova
Kuwait Cancer Control Center, Laboratory of Cancer Genetics, Department of Hematology, Shuwaikh,
70653, Kuwait (AZ)
Published in Atlas Database: March 2010
Online updated version : http://AtlasGeneticsOncology.org/Anomalies/der6t0106q21p21ID1546.html
DOI: 10.4267/2042/44925
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 2.0 France Licence.
© 2010 Atlas of Genetics and Cytogenetics in Oncology and Haematology
Identity
Partial karyotypes showing the chromosomal translocation der(6)t(1;6)(q21-23;p21) identified by G-banding.
years old male, progressed to AML. From the known
data of 14 patients with myelofibrosis, median age was
65.5 years (range, 38-72 years).
Clinics and pathology
Disease
Clinics
Most frequently observed in chronic myeloproliferative
disorders, occurs with higher frequency in patients with
chronic idiopathic myelofibrosis, polycythemia vera
and post-polycythemic myelofibrosis; may be present
either at diagnosis or during transformation to
advanced stages of the disease.
In the largest study, the anomaly was associated with
splenomegaly, elevated WBC count, elevated levels of
alkaline phosphatase and lactate dehydrogenase;
median overall survival was 7.8 years: five patients
have died (one transformed to acute myeloid leukemia
and the others died because of sepsis or thrombosis).
Epidemiology
Described in 20 cases (11 males, 9 females): 1
biphenotypic leukemia (16 years old male); 1 B-cell
lymphoma (73 years old female); 2 acute myeloid
leukemia (AML) patients (1 male 71 years old, 1
female 28 years old); and in 16 patients with
myelofibrosis with myeloid metaplasia (9 males; 7
females): eleven patients had myelofibrosis with
myeloid metaplasia, three post-polycythemic myeloid
metaplasia, and one post-thrombocythemic myeloid
metaplasia; one of these patients, a 47
Atlas Genet Cytogenet Oncol Haematol. 2010; 14(12)
Cytogenetics
Cytogenetics morphological
Breakpoints may be controversial and difficult to
ascertain in poor quality preparations. Recently, the
same breakpoint on 6p21.3 and clustering of
breakpoints near the paracentric region 1q21-23 was
described in 14 patients with myelofibrosis with
myelocytic metaplasia.
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der(6)t(1;6)(q21-23;p21)
Zamecnikova A
the underlying molecular consequences
rearrangement remain to be determined.
Additional anomalies
Sole anomaly in 9 cases (2 AML and 7 cases with
myelofibrosis); no recurrent additional anomaly
observed in patients with complex karyotypes. 4
patients had two or more different clones (1 patient
with biphenotypic leukemia and 3 myelofibrosis cases);
among them 2 patients had 1q21-23 rearrangements
involving the homologous chromosome 1.
the
To be noted
Case Report
der(6)t(1;6)(q21;p21)
polycythemia vera.
in
myelofibrosis
following
References
Result of the chromosomal
anomaly
Mertens F, Johansson B, Heim S, Kristoffersson U, Mitelman
F. Karyotypic patterns in chronic myeloproliferative disorders:
report on 74 cases and review of the literature. Leukemia.
1991 Mar;5(3):214-20
Fusion protein
Reilly JT, Snowden JA, Spearing RL, Fitzgerald PM, Jones N,
Watmore A, Potter A. Cytogenetic abnormalities and their
prognostic significance in idiopathic myelofibrosis: a study of
106 cases. Br J Haematol. 1997 Jul;98(1):96-102
Oncogenesis
The presence of the der(6)t(1;6) results in partial
trisomy for 1q21-23 to 1qter and in loss of 6p21 to
6pter. The pathogenetic significance may be the
consequence of gain of gene(s) on 1q and/or haploinsufficiency of gene(s) from 6p and alternatively,
rearrangements of one or more genes at the
breakpoints. The significance of the 6p21 breakpoint is
unclear; however a number of published reports of
myelofibrosis with chromosome 6p breakpoints in the
region raise the possibility of a gene involved in the
pathogenesis of this hematologic disorder. The inability
to identify common breakpoints on 1q, suggests that an
increase in gene copy number is a pathogenetic event.
Whether trisomy 1q is a secondary event to a primary
(cryptic? e.g. JAK2 V617F mutation) anomaly as well
as the roles of methylation, cytotoxic treatments and
Atlas Genet Cytogenet Oncol Haematol. 2010; 14(12)
of
Andrieux J, Demory JL, Caulier MT, Agape P, Wetterwald M,
Bauters F, Laï JL. Karyotypic abnormalities in myelofibrosis
following polycythemia vera. Cancer Genet Cytogenet. 2003
Jan 15;140(2):118-23
Dingli D, Grand FH, Mahaffey V, Spurbeck J, Ross FM,
Watmore AE, Reilly JT, Cross NC, Dewald GW, Tefferi A.
Der(6)t(1;6)(q21-23;p21.3): a specific cytogenetic abnormality
in myelofibrosis with myeloid metaplasia. Br J Haematol. 2005
Jul;130(2):229-32
Hussein K, Van Dyke DL, Tefferi A. Conventional cytogenetics
in myelofibrosis: literature review and discussion. Eur J
Haematol. 2009 May;82(5):329-38
This article should be referenced as such:
Zamecnikova A. der(6)t(1;6)(q21-23;p21). Atlas
Cytogenet Oncol Haematol. 2010; 14(12):1175-1176.
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