Atlas of Genetics and Cytogenetics in Oncology and Haematology
t(3;7)(q26;q21)
| Identity |
 | |
| Partial karyotype showing an unbalanced t(3;7)(q26;q21) | |
| Clinics and Pathology |
| Note | This translocation has been observed in myeloid leukemia [one case of acute myeloid leukemia (AML), subtype M4, and two cases of chronic myeloid leukemia in blast crisis (CML-BC)] |
| Disease | blast crisis chronic myelogenous leukemia (myeloid-myeloid/NK phenotype) |
| Phenotype / cell stem origin | myeloid leukemia |
| Prognosis | poor |
| Disease | AML M4 |
| Phenotype / cell stem origin | Acute myeloid leukemia |
| Prognosis | poor |
| Cytogenetics |
| Cytogenetics Morphological | t(3;7)(q26;q21) in BC-CML; -7,+der(7)t(3;7)(q26;q21) in AML M4 |
 | |
| FISH cohybridization between clones identifying breakpoints on chromosome 3 (RP11-33A1) and 7 (RP11-332M5) in a case of BC-CML with a t(3;7)(q21;q26). | |
| Probes | RP11-33A1 (EVI1) RP11-332M5 (CDK6) |
| Additional anomalies | Sole anomaly in AML; Ph chromosome in BC-CML patients |
| Variants | No variants described. |
| Genes involved and Proteins |
| Gene Name | EVI1 (ecotropic viral integration site 1, alias PRDM3) |
| Location | 3q26.2 |
| Note | EVI1 is expressed at very low levels in normal peripheral blood and bone marrow. The gene is overexpressed in myeloid leukemias and myelodysplastic syndromes as a result of chromosomal rearrangements at either the 5' region of the gene in t(3;3)(q21;q26) or at the 3' region in inv(3)(q21q26) by juxtaposition of the gene to putative enhancer elements of the Ribophorin I gene in 3q21. High expression of EVI1 can also occur in the t(3;21)(q26;q22) as part of the fusion gene AML1/MDS1/EVI1 in CML-BC, or MDS or as part of the fusion gene ETV6/MDS1/EVI1 in AML with t(3;12) translocation. EVI1 is also involved in other translocations such as t(2;3)(p13;q26), t(2;3)(q23;q26), t(3;17)(q26;q22) and t(3;13)(q26;q13-14). Other studies have reported abnormal expression of EVI1 in MDS and AML without 3q26 structural abnormalities, suggesting that inappropriate activation of this gene occurs through various mechanisms. |
| Dna / Rna | 16 exons spanning 64.2 Kb. Transcriptional orientation is from telomere to centromere. 6 splicing variants. |
| Protein | 1051 amino acids; 118335 Da. Nuclear location, contains 10 C2H2-type zinc fingers. |
| Gene Name | CDK6 (cyclin-dependent kinase 6, alias PLSTIRE) |
| Location | 7q21.2 |
| Dna / Rna | 7 exons spanning 229 Kb. Transcriptional orientation is from telomere to centromere. |
| Protein | 326 amino acids; 36938 Da. It belongs to the Ser/Thr protein kinase family, CDC2/CDKX subfamily. It is probably involved in the control of the cell cycle. Interacts with D-type G1 cyclins. |
| Result of the chromosomal anomaly |
| Note | overexpression of EVI1 in bone marrow; no detected CDK6/EVI1 fusion gene in any of the myeloid leukemia cases analyzed. |
| External links |
| Other database | t(3;7)(q26;q21) | Mitelman database (CGAP - NCBI) | |
| Other database | t(3;7)(q26;q21) | CancerChromosomes (NCBI) |
| To be noted |
| Additional cases are needed to delineate the epidemiology of this rare entity: you are welcome to submit a paper to our new Case Report section. |
| Bibliography |
| A novel chromosomal translocation t(3;7)(q26;q21) in myeloid leukemia resulting in overexpression of EVI1. |
| Storlazzi CT, Anelli L, Albano F, Zagaria A, Ventura M, Rocchi M, Panagopoulos I, Pannunzio A, Ottaviani E, Liso V, Specchia G |
| Annals of hematology. 2004 ; 83 (2) : 78-83. |
| PMID 14551738 |
| Myeloid/natural killer cell blast crisis representing an additional translocation, t(3;7)(q26;q21) in Philadelphia-positive chronic myelogenous leukemia. |
| Henzan H, Yoshimoto G, Okeda A, Nagasaki Y, Hirano G, Takase K, Tanimoto T, Miyamoto T, Fukuda T, Nagafuji K, Harada M |
| Annals of hematology. 2004 ; 83 (12) : 784-788. |
| PMID 15322764 |
| Contributor(s) |
| Written | 08-2005 | Clelia Tiziana Storlazzi, Francesco Albano |
| Department of Genetics and Microbiology, University of Bari, Via Amendola 165/A, 70126 Bari, Italy |
| Citation |
| This paper should be referenced as such : |
| Storlazzi CT, Albano F . t(3;7)(q26;q21). Atlas Genet Cytogenet Oncol Haematol. August 2005 . URL : http://AtlasGeneticsOncology.org/Anomalies/t0307q26q21ID1287.html |
| © Atlas of Genetics and Cytogenetics in Oncology and Haematology | indexed on : Mon May 12 18:12:11 2008 |
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