t(6;11)(q13;q23) KMT2A/SMAP1

2007-10-01   Jean-Loup Huret 

1.Genetics, Dept Medical Information, University of Poitiers, CHU Poitiers Hospital, F-86021 Poitiers, France

Clinics and Pathology


Acute leukemia


Only 2 cases to date; one of which was not further described.

Phenotype stem cell origin

One case was a M4 acute myeloid leukaemia.


The patient was a 14 year old girl


Survival was 18 months in the only documented case.

Genes Involved and Proteins

Gene name
SMAP1 (stromal membrane-associated protein 1)
Protein description
SMAP1 is a GTPase-activating protein (GAP) for Arf6.
Vesicle formation requires clathrin, its adaptors, and an enzymatic activity. This is given by small GTPase ADP-ribosylation factors (Arf; there is six Arfs, Arf1, Arf3, Arf2/Arf4, Arf5 and Arf6). Arf switches between a GTP-bound active state (regulated by guanine-nucleotide exchange factor (GEF)) and a GDP-bound inactive state (regulated by GTPase-activating protein (GAP)).
Arf6/SMAP1 regulates the clathrin dependent endocytosis of vesicles from the plasma membrane and the recycling of endosome to the plasma membrane.
Gene name
KMT2A (myeloid/lymphoid or mixed lineage leukemia)
Protein description
transcriptional regulatory factor; MLL may have yin-yang functions though actions of MLL-N and MLL-C (e.g. desacetylation/acetylation); MLL-N acts as a transcriptional repressor; MLL can be associated with more than 30 proteins, including the core components of the SWI/SNF chromatin remodeling complex and the transcription complex TFIID. MLL binds promotors of HOX genes through acetylation and methylation of histones. MLL is a major regulator of hematopoesis and embryonic development, through regulation of HOX genes expression regulation ( HOXA9 in particular).

Result of the Chromosomal Anomaly




Pubmed IDLast YearTitleAuthors
95932861998Ten novel 11q23 chromosomal partner sites. European 11q23 Workshop participants.Harrison CJ et al
121191102002Cloning, characterization and chromosome mapping of the human SMAP1 gene.Marcos I et al
156267572005Diagnostic tool for the identification of MLL rearrangements including unknown partner genes.Meyer C et al
165716802006SMAP2, a novel ARF GTPase-activating protein, interacts with clathrin and clathrin assembly protein and functions on the AP-1-positive early endosome/trans-Golgi network.Natsume W et al
156596522005A novel GTPase-activating protein for ARF6 directly interacts with clathrin and regulates clathrin-dependent endocytosis.Tanabe K et al


Jean-Loup Huret

t(6;11)(q13;q23) KMT2A/SMAP1

Atlas Genet Cytogenet Oncol Haematol. 2007-10-01

Online version: http://atlasgeneticsoncology.org/haematological/1408/t(6;11)(q13;q23)