| Written | 2010-03 | Adriana Zamecnikova |
| Kuwait Cancer Control Center, Laboratory of Cancer Genetics, Department of Hematology, Shuwaikh, 70653, Kuwait |
| Identity |
| ICD-Topo | C420,C421,C424 BLOOD, BONE MARROW, & HEMATOPOIETIC SYS |
| ICD-Morpho | 9975/3 Chronic myelogenous leukaemia, BCR-ABL1 positive; Myeloproliferative neoplasm, unclassifiable; Myelodysplastic/myeloproliferative neoplasm, unclassifiable |
| Atlas_Id | 1546 |
 | |
| Partial karyotypes showing the chromosomal translocation der(6)t(1;6)(q21-23;p21) identified by G-banding. | |
| Clinics and Pathology |
| Disease | 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. |
| 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 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 | 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). |
| 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. |
| 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. |
| Result of the chromosomal anomaly |
| 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 haplo-insufficiency 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 the underlying molecular consequences of the rearrangement remain to be determined. |
| To be noted |
| Case Report | der(6)t(1;6)(q21;p21) in myelofibrosis following polycythemia vera |
| Bibliography |
| Karyotypic abnormalities in myelofibrosis following polycythemia vera. |
| Andrieux J, Demory JL, Caulier MT, Agape P, Wetterwald M, Bauters F, Lai JL. |
| Cancer Genet Cytogenet. 2003 Jan 15;140(2):118-23. |
| PMID 12645649 |
| Der(6)t(1;6)(q21-23;p21.3): a specific cytogenetic abnormality in myelofibrosis with myeloid metaplasia. |
| Dingli D, Grand FH, Mahaffey V, Spurbeck J, Ross FM, Watmore AE, Reilly JT, Cross NC, Dewald GW, Tefferi A. |
| Br J Haematol. 2005 Jul;130(2):229-32. |
| PMID 16029451 |
| Conventional cytogenetics in myelofibrosis: literature review and discussion. |
| Hussein K, Van Dyke DL, Tefferi A. |
| Eur J Haematol. 2009 May;82(5):329-38. Epub 2009 Jan 9. |
| PMID 19141119 |
| Karyotypic patterns in chronic myeloproliferative disorders: report on 74 cases and review of the literature. |
| Mertens F, Johansson B, Heim S, Kristoffersson U, Mitelman F. |
| Leukemia. 1991 Mar;5(3):214-20. |
| PMID 2013980 |
| Cytogenetic abnormalities and their prognostic significance in idiopathic myelofibrosis: a study of 106 cases. |
| Reilly JT, Snowden JA, Spearing RL, Fitzgerald PM, Jones N, Watmore A, Potter A. |
| Br J Haematol. 1997 Jul;98(1):96-102. |
| PMID 9233570 |
| Citation |
| This paper should be referenced as such : |
| Zamecnikova, A |
| der(6)t(1;6)(q21-23;p21) |
| Atlas Genet Cytogenet Oncol Haematol. 2010;14(12):1175-1176. |
| Free journal version : [ pdf ] [ DOI ] |
| On line version : http://AtlasGeneticsOncology.org/Anomalies/der6t0106q21p21ID1546.html |
| Translocations implicated (Data extracted from papers in the Atlas) |
| der(6)t(1;6)(q21;p21) | |
| External links |
| REVIEW articles | automatic search in PubMed |
| Last year articles | automatic search in PubMed |
| All articles | automatic search in PubMed |
| © Atlas of Genetics and Cytogenetics in Oncology and Haematology | indexed on : Mon Jul 9 10:10:27 CEST 2018 |
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