2008-06-01   Marta Susana Gallego 

1.Laboratorio de Citogenetica - Servicio de Genetica - Hospital de Pediatria Prof Dr JPGarrahan, Buenos Aires, Argentina

Clinics and Pathology


Acute lymphoblastic leukemia (ALL)

Phenotype stem cell origin

B-cell precursor (pro-B, common, pre-B) and exceptionally T ALL.


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.


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.


The clinical characteristics are virtually unknown.


Remains to be determined. The median survival of the reported cases varies from 7 to 40 months.


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 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

Gene name
Not yet defined.


Pubmed IDLast YearTitleAuthors
15343891992Morphologic, immunologic and cytogenetic studies in children with acute lymphoblastic leukemia at diagnosis and relapse: a Pediatric Oncology Group study.Abshire TC et al
75793551995Loss 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 p27KIP1.Cavé H et al
86252241995Adult acute lymphoblastic leukemia at relapse. Cytogenetic, immunophenotypic, and molecular changes.Chucrallah AE et al
159912232004Increased expression of AML1-a and acquired chromosomal abnormalities in childhood acute lymphoblastic leukemia.Gutiérrez-Angulo M et al
69529601982Correlation of karyotype with clinical features in acute lymphoblastic leukemia.Kaneko Y et al
151727542004Aberrations involving 13q12 approximately q14 are frequent secondary events in childhood acute lymphoblastic leukemia.Kovacs BZ et al
88895031996Isochromosomes in acute lymphoblastic leukaemia: i(21q) is a significant finding.Martineau M et al
78191021994Metaphase fluorescence in situ hybridization (FISH) in the follow-up of 60 patients with haemopoietic malignancies.Nylund SJ et al
162133622005Detection 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 et al
31632591988Nonrandom chromosomal abnormalities in acute lymphoblastic leukemia of childhood.Prigogina EL et al
15715501992Isochromosomes in childhood acute lymphoblastic leukemia: a collaborative study of 83 cases.Pui CH et al
167906932007Chromosome 6p amplification and cancer progression.Santos GC et al
76214181995Isochromosome 6p and deletion of 6q characterize two related cytogenetic clones in a patient with immunoblastic lymphoma.Scaravaglio P et al
182975242008Characterization of 6q deletions in mature B cell lymphomas and childhood acute lymphoblastic leukemia.Thelander EF et al
29103651989Immunophenotype-karyotype associations in human acute lymphoblastic leukemia.Uckun FM et al


Atlas Image
Partial GTG banded karyotype showing i(6)(p10). Courtesy of Cytogenetics Laboratory, Garrahan Pediatrics Hospital, Buenos Aires, Argentina.


Marta Susana Gallego


Atlas Genet Cytogenet Oncol Haematol. 2008-06-01

Online version: http://atlasgeneticsoncology.org/haematological/1053/i(6)(p10)