| Written | 2008-06 | Marta Susana Gallego |
| Laboratorio de Citogenetica - Servicio de Genetica - Hospital de Pediatria Prof Dr JPGarrahan, Buenos Aires, Argentina |
| Identity |
| ICD-Topo | C420,C421,C424 BLOOD, BONE MARROW, & HEMATOPOIETIC SYS |
| ICD-Morpho | 9811/3 B lymphoblastic leukaemia/lymphoma, NOS |
| ICD-Morpho | 9837/3 T lymphoblastic leukaemia/lymphoma |
| Atlas_Id | 1053 |
 | |
| Partial GTG banded karyotype showing i(6)(p10). Courtesy of Cytogenetics Laboratory, Garrahan Pediatrics Hospital, Buenos Aires, Argentina. | |
| Clinics and Pathology |
| Disease | Acute lymphoblastic leukemia (ALL) |
| Phenotype / cell stem origin | B-cell precursor (pro-B, common, pre-B) and exceptionally T ALL. |
| Etiology | It has been suggested that, although the isochromosomes are rarely the sole abnormality in the majority of cases, they do occur early in the leukemic process. Martineau et al. proposed that isochromosomes are mechanical indicators of genetic events central to the etiology of the leukemia. |
| Epidemiology | Isochromosomes are a nonrandom chromosomal anomaly in ALL. The incidence of i(6)(p10) in ALL is 0.07%. Only sixteen cases have been reported in ALL and only one in immunoblastic lymphoma. All the patients, except for one adult, were children with a median age of 5 years; sex ratio: 12M/5F. |
| Clinics | The clinical characteristics are virtually unknown. |
| Prognosis | Remains to be determined. The median survival of the reported cases varies from 7 to 40 months. |
| Genetics |
| It has been suggested that a central part of the short arm of chromosome 6p harbours one or more oncogenes directly involved in tumour progression. On the other hand, despite accumulating evidence those deletions of chromosomal bands 6q16-q21 are a critical event in ALL, no suppressor genes have been identified in this region. Recently, it has been described that a minimal deleted interval in 6q21 encompasses the FOXO3A, PRDM1 and HACE1 candidate genes. |
| Cytogenetics |
| Note | The isochromosome 6p was found in the stemline in 12 cases and in a sideline in 5 cases. It was associated with pseudo, hyper and hypodiploidies and high ploidies. It occured more frequently at diagnosis than at relapse. |
| Cytogenetics Molecular | Comparative genomic hybridisation studies have detected copy-number increases affecting chromosome 6p in several types of cancer. |
| Additional anomalies | The isochromosome 6p was not observed as a sole anomaly. The majority of cases are part of a complex karyotype and some cases occur with established abnormalities such as der(19)t(1;19), t(12;21)(p13;q22) and t(14;18)(q32;q21). |
| Genes involved and Proteins |
| Note | Not yet defined |
| Gene Name | Not |
| Result of the chromosomal anomaly |
| Note | As a result of the formation of the isochromosome, the structural abnormality results in monosomy for the genes on the long arm, and trisomy for the genes in the short arm. It is not known whether the overexpression of a proto-oncogene or the deletion of a tumour-suppressor gene from the isochromosome contributes to development of proliferation of leukaemia. |
| 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 |
| Morphologic, immunologic and cytogenetic studies in children with acute lymphoblastic leukaemia at diagnosis and relapse: a Pediatric Oncology Group study. |
| Abshire TC, Buchanan GR, Jackson JF, Shuster JJ, Brock B, Head D, Behm F, Crist WM, Link M, Borowitz M, Pullen DJ. |
| Leukemia 1992; 6 (5): 357-362. |
| PMID 1534389 |
| Loss of heterozygosity in the chromosomal region 12p12-13 is very common in childhood acute lymphoblastic leukemia and permits the precise localization of a tumor-suppressor gene distinct from p7KIP1. |
| Cavé H, Gérard B, Martin E, Guidal C, Devaux I, Weissenbach J, Elion J, Vilmer E, Grandchamp B. |
| Blood 1995; 86(10): 3869-3875. |
| PMID 7579355 |
| Adult acute lymphoblastic leukemia at relapse. Cytogenetic, immunophenotypic and molecular changes. |
| Chucrallah AE, Stass SA, Huh YO, Albitar M, Kantarjian HM. |
| Cancer 1995; 76(6): 985-991. |
| PMID 8625224 |
| Increased expression of AML1-a and acquired chromosomal abnormalities in childhood acute lymphoblastic leukemia. |
| Gutierrez-Angulo M, Gonzalez-Garcia JR, Meza-Espinoza JP, Picos-Cardenas VJ, Esparza-Flores MA, Lopez-Guido B, Rivera H. |
| Hematol Oncol 2004; 22: 85-90. |
| PMID 15991223 |
| Correlation of karyotype with clinical features in acute lymphoblastic leukaemia. |
| Kaneko Y, Rowley JD, Variakojis D, Chilcote RR, Check I, Sakurai M. |
| Cancer Res 1982; 42: 2918-2929. |
| PMID 6952960 |
| Aberrations involving 13q12-q14 are frequent secondary events in childhood acute lymphoblastic leukemia. |
| Kovacs BZ, Niggli FK, Betts DR. |
| Cancer Genet Cytogenet 2004; 151: 157-161. |
| PMID 15172754 |
| Isochromosomes in acute lymphoblastic leukemia: i(21q) is a significant finding. |
| Martineau M, Clark R, Farrell DM, Hawkins JM, Moorman AV, Secker-Walker LM. |
| Genes Chromosomes Cancer 1996; 17: 21-30. |
| PMID 8889503 |
| Metaphase fluorescence in situ hybridization (FISH) in the follow-up of 60 patients with haematopoietic malignancies. |
| Nylund SJ, Ruutu T, Saarinen U, Knuutila S. |
| Br J Haematol 1994; 88: 778-783. |
| PMID 7819102 |
| Detection of ETV6 and RUNX1 gene rearrangements using fluorescence in situ hybridization in Mexican patients with acute lymphoblastic leukemia: experience at a single institution. |
| Pérez-Vera P, Montero-Ruiz O, Frías S, Ulloa-Avilés V, Cárdenas-Cardó R, Paredes-Aguilera R, Rivera-Luna R, Carnevale A. |
| Cancer Genet Cytogenet 2005; 162: 140-145. |
| PMID 16213362 |
| Nonrandom chromosomal abnormalities in acute lymphoblastic leukaemia of childhood. |
| Prigogina EL, Puchkova GP, Mayakova SA. |
| Cancer Genet Cytogenet 1988; 32: 183-203. |
| PMID 3163259 |
| Isochromosomes in childhood acute lymphoblastic leukemia: a collaborative study of 83 cases. |
| Pui C-H, Carroll AJ, Raimondi SC, Schell MJ, Head DR, Shuster JJ, Crist WM, Borowitz MJ, Link MP, Behm FG, Steuber CP, Land VJ. |
| Blood 1992; 79: 2384-2391. |
| PMID 1571550 |
| Chromosome 6p amplification and cancer progression. |
| Santos GC, Zielenska M, Prasad M, Squire JA. |
| J Clin Pathol. 2007; 60(1): 1-7. |
| PMID 16790693 |
| Isochromosome 6p and deletion of 6q characterize two related cytogenetic clones in a patient with immunoblastic lymphoma. |
| Scaravaglio P, Saglio G, Geuna M, Palestro G, Guglielmelli T, Rege-Cambrin G. |
| Cancer Genet Cytogenet. 1995; 81(2): 179-81. |
| PMID 7621418 |
| Characterization of 6q deletions in mature B cell lymphomas and childhood acute lymphoblastic leukemia. |
| Thelander EF, Ichimura K, Corcoran M, Barbany G, Nordgren A, Heyman M, Berglund M, Mungall A, Rosenquist R, Collins VP, Grander D, Larsson C, Lagercrantz S. |
| Leuk Lymphoma. 2008; 49(3): 477-87. |
| PMID 18297524 |
| Immunophenotype-karyotype associations in human acute lymphoblastic leukaemia. |
| Uckun FM, Gajl-Peczalska KJ, Provisor AJ, Heerema NA. |
| Blood 1989; 73: 271-280. |
| PMID 2910365 |
| Citation |
| This paper should be referenced as such : |
| Gallego, MS |
| i(6)(p10) |
| Atlas Genet Cytogenet Oncol Haematol. 2009;13(6):434-435. |
| Free journal version : [ pdf ] [ DOI ] |
| On line version : http://AtlasGeneticsOncology.org/Anomalies/i6p10ID1053.html |
| Translocations implicated (Data extracted from papers in the Atlas) |
| i(6)(p10) | |
| 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 : Fri Jun 30 11:22:21 CEST 2017 |
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