t(11;16)(q23;p13.3) KMT2A/CREBBP

2009-03-01   Elise Labis 

1.Laboratory of Medical Genetics, Hospital Jeanne de Flandre, University Hospital Regional Center-CHRU, Avenue Eugène Avinée, 59037 Lille cedex, France

Clinics and Pathology

Disease

Treatment-related myelodysplastic syndrome (t-MDS) or treatment-related acute leukaemia, usually myeloblastic (t-AML), less often lymphoblastic (t-ALL).
Two case reports describe a de novo leukaemia with t(11;16)(q23;p13.3): an AML-M4 (Glassman et al., 2003) and an infant ALL, which switch into AML with retention of the translocation (Stasik et al., 2006).

Phenotype stem cell origin

Variable phenotypes: most often LAM4 in t-AML (but also LAM5a and LAM2); chronic myelomonocytic leukaemia (CMMoL) in t-MDS.

Etiology

Chemotherapy for other primary malignancies (including leukaemia, lymphoma and solid tumors) using topoisomerase II inhibitors (epipodophyllotoxins or anthracyclins).

Epidemiology

Rare translocation (about twenty cases described), found at any age, from infancy to elder age.

Prognosis

Poor, as in other therapy-related leukaemia.

Cytogenetics

Cytogenetics morphological

Can be seen with G-banding: chromosome 11 appears shortened, chromosome 16 enlarged (11q- and 16p+).

Cytogenetics molecular

FISH may be needed.
Atlas Image
Fish studies using a commercially available MLL break-apart probe (Vysis® LSI® MLL Dual Color). The derivative 11 shows a single green signal indicating rearrangement of the MLL locus. The derivative 16 has the translocated portion of the MLL indicated by a single red signal.

Additional anomalies

In half cases about, no recurrent additional cytogenetic anomalies.

Genes Involved and Proteins

Gene name
KMT2A (myeloid/lymphoid or mixed lineage leukemia)
Location
11q23.3
Dna rna description
37 exons, spanning over 100 kb.
Protein description
MLL is a "multipartner" gene involved in multiple rearrangements: the most frequent partners are AF4 in 4q21, AF6 in 6q27, AF9 in 9p22, ELL in 19p13.1 and ENL in 19p13.3.
MLL is a major regulator of hematopoesis and embryonic development, through HOX genes expression regulation. MLL binds to promotors of HOX genes such as Hoxa7 and Hoxa9 (proteins which regulate hematopoiesis and are normally expressed only in early hematopoietic progenitors) through acetylation and methylation of histones.
Gene name
CREBBP (CREB binding protein)
Location
16p13.3
Dna rna description
About 154 kb, 32 exons.
Protein description
It is a transcriptional coactivator involved in coordonating signal from many sequence-specific activators to modulate transcription and/or cell cycle progression. It has endogenous histone acetyltransferase activity and may contribute to transcriptional regulation via targeted acetylation of chromatin.

Result of the Chromosomal Anomaly

Transcript

5 MLL - 3 CBP on the der(11) and 5 CBP - 3 MLL on the der(16).
Variable breakpoints: In MLL, almost all of the breakpoints occurs in an 8.3-kb fragment known as the breakpoint cluster region (BCR), encompassing exons 8-14. In CBP, the genomic breakpoints clustered in an 8.2-kb region of intron 3 (BCR 8.2kb), which is different of the breakpoints in CBP for patients with t(8;16) clustered in a 2.3-kb region in intron 2 (BCR 2.3kb).

Description

N-Term from MLL (containing the AT-hooks and repression domain) fused to the C-Term of CBP (almost always including the CREB binding domain, bromodomain, histone acetyltransferase domain).

Bibliography

Pubmed IDLast YearTitleAuthors
129564432003Translocation (11;16)(q23;p13) acute myelogenous leukemia and myelodysplastic syndrome.Glassman AB et al
92261521997All patients with the T(11;16)(q23;p13.3) that involves MLL and CBP have treatment-related hematologic disorders.Rowley JD et al
168431042006Infant acute lymphoblastic leukemia with t(11;16)(q23;p13.3) and lineage switch into acute monoblastic leukemia.Stasik C et al
153345492004Characterization of genomic breakpoints in MLL and CBP in leukemia patients with t(11;16).Zhang Y et al

Summary

Fusion gene

KMT2A/CREBBP KMT2A (11q23.3) CREBBP (16p13.3) COF 1874 1875 1876 2093 2095 2097 2098 2109 2110 2116 2117|KMT2A/CREBBP KMT2A (11q23.3) CREBBP (16p13.3) TIC
Atlas Image
t(11;16)(q23;p13.3) G-banding.

Citation

Elise Labis

t(11;16)(q23;p13.3) KMT2A/CREBBP

Atlas Genet Cytogenet Oncol Haematol. 2009-03-01

Online version: http://atlasgeneticsoncology.org/haematological/1120/t(11;16)(q23;p13-3)-kmt2a-crebbp

External Links