Atlas of Genetics and Cytogenetics in Oncology and Haematology

Home   Genes   Leukemias   Solid Tumors   Cancer-Prone   Deep Insight   Case Reports   Journals  Portal   Teaching   

X Y 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 NA

t(14;18)(q32;q21) IGH/BCL2

t(2;18)(p11;q21) IGK/BCL2

t(18;22)(q21;q11) IGL/BCL2

Written1998-05Jean-Loup Huret
Genetics, Dept Medical Information, University of Poitiers, CHU Poitiers Hospital, F-86021 Poitiers, France

(Note : for Links provided by Atlas : click)


ICD-Morpho 9811/3 B lymphoblastic leukaemia/lymphoma, NOS
Atlas_Id 2006
Note the 3 translocations are variants of each other, and they share the same clinical significance
  t(14;18)(q32;q21) IGH/BCL2 , t(2;18)(p11;q21), t(18;22)(q21;q11), BCL2 Top: 14;18)(q32;q21), G- banding - Courtesy Jean-Luc Lai and Alain Vanderhaegen (left), and H. Norback, Eric B. Johnson, Sara Morrison-Delap UW Cytogenetic Services (centre); - Courtesy Adriana Zamecnikova (bottom tree); R- banding - Jean Loup Huret (top), and Courtesy Hossein Mossafa (bottom). FISH - Courtesy Hossein Mossafa (center); Hybridization with Vysis LSI IGH/BCL dual color probe (Abbott Molecular, US) showing fused yellow signals on der(14) and der(18) chromosomes - Courtesy Adriana Zamecnikova. Middle: t(2;18)(p11;q21), G- banding - Courtesy Jean-Luc Lai and Alain Vanderhaegent. Bottom: t(18;22)(q21;q11), G- banding - Courtesy Jean-Luc Lai and Alain Vanderhaegen (left) ; and, H. Norback, Eric B. Johnson, Sara Morrison-Delap UW Cytogenetic Services (centre). BCL2: BAC248E24 (BCL2, 18q21, green) cohybridized with PAC PAC 998D24 (14q32.3, red, centromeric to the breakpoint) - Courtesy Mariano Rocchi, Resources for Molecular Cytogenetics

Clinics and Pathology

Disease B- cell NHL mainly; may (rarely) be found in ALL or in chronic lymphoproliferative diseases
Phenotype / cell stem origin B lymphocyte; the translocation occurs at the pre B cell stage
Epidemiology found in 80 to 90 % of follicular lymphomas, 30% of diffuse large cell lymphomas (sometimes with prior follicular type), rarely in other lymphoproliferative disorders
Prognosis small cleaved cell follicular lymphomas have a slow evolutivity and a median survival of 10 yrs or more; large cell lymphomas have a worse prognosis; the t(14;18) may have little or no prognostic significance, which would be in accordance with its 'oncogenic' role (see below)


  BAC248E24 (BCL2, 18q21, green) cohybridized with PAC PAC 998D24 (14q32.3, red, centromeric to the breakpoint) - Courtesy Mariano Rocchi, Resources for Molecular Cytogenetics
Cytogenetics Morphological the t(14;18) is well recognized with G-banding, may be overlocked with R-banding; the t(2;18)( p11;q21) and the t(18;22(q21;q11) are rare variants
Additional anomalies found in 90% of cases; complex karyotypes are frequent; by decreasing order, +7, del(6q), +12, + X, + 18, +5, +8, + der(18), + 21 are found in 25 to 10% of cases; +X and del(6q) more frequently in low grade, +7,+8, +der(18), and also the addition of a t(8;14)(q24;q32) more often in high grade NHL

Genes involved and Proteins

Gene NameIGH (Immunoglobulin Heavy)
Location 14q32.33
Dna / Rna IGH is composed of IGHV genes, IGHD segments, IGHJ segments, and IGHC genes.
Protein IGH encodes the immunoglobulin heavy chains. They result from the DNA rearrangement (with deletion of the intermediary DNA) of IGHV, IGHD and IGHJ; an additional DNA rearrangement (switch) with constant genes IGHM --> IGHG, IGHA and IGHE can occur.
Gene NameBCL2 (B-cell leukemia/lymphoma 2)
Location 18q21.33
Dna / Rna 3 exons; 2 alternative transcripts (a and b)
Protein member of the BCL2 family (with BAX, BCLX,...); contains dimerization domains (BH) and NH domains; BCL2a contains a hydrophobic tail for membrane anchorage; inhibits cell death process through heterodimerization

Result of the chromosomal anomaly

Hybrid gene
Description 5' BCL2 translocated on chromosome 14 near JH (junctions genes of IgH) and C in 3'; the breakpoint in BCL2 is either in the 3' untranslated region of exon 3 (major breakpoint region (MBR) in 70% of cases) or more distal, in 3' of exon 3 (minor cluster region (MCR) in the remaining 30%); illegitimate recombination
Fusion Protein
Description no fusion protein, but promoter exchange; the immunoglobulin gene enhancer stimulates the expression of BCL2
Oncogenesis as BCL2 is an apoptosis inhibitor, cell death is delayed, and there is cell accumulation more than real transformation (clones of long living B-cells with t(14;18) may even be seen in the normal population, and with frequency increasing with age)


Cytogenetics of lymphomas: a brief review of its theoretical and practical significance.
Donner LR
Cancer genetics and cytogenetics. 1997 ; 94 (1) : 20-26.
PMID 9078287
Cytogenetic evolution patterns in non-Hodgkin's lymphoma.
Johansson B, Mertens F, Mitelman F
Blood. 1995 ; 86 (10) : 3905-3914.
PMID 7579360
Cytogenetic mechanisms in the pathogenesis and progression of follicular lymphoma.
Knutsen T
Cancer surveys. 1997 ; 30 : 163-192.
PMID 9547992
Non-Hodgkin's lymphoma.
Maloney DG
Current opinion in hematology. 1995 ; 2 (4) : 255-261.
PMID 9372005


This paper should be referenced as such :
Huret, JL
t(14;18)(q32;q21) - t(2;18)(p11;q21) - t(18;22)(q21;q11)
Atlas Genet Cytogenet Oncol Haematol. 1998;2(4):134-136.
Free journal version : [ pdf ]   [ DOI ]
On line version :

Translocations implicated (Data extracted from papers in the Atlas)

 t(14;18)(q32;q21) IGH/BCL2
 t(18;22)(q21;q11) IGL/BCL2
 t(2;18)(p11;q21) IGK/BCL2

External links

IGK (14q32.33) BCL2 (18q21.33)

Mitelman databaset(14;18)(q32;q21) [Case List]    t(14;18)(q32;q21) [Transloc-MCList] IGH/BCL2 [Fusion-MCList]
Mitelman databaset(18;22)(q21;q11) [Case List]    t(18;22)(q21;q11) [Transloc-MCList] IGL/BCL2 [Fusion-MCList]
Mitelman databaset(2;18)(p11;q21) [Case List]    t(2;18)(p11;q21) [Transloc-MCList] IGK/BCL2 [Fusion-MCList]
arrayMap (UZH-SIB Zurich)Topo ( C42) Morph ( 9811/3) -   [auto + random 100 samples .. if exist ]   [tabulated segments]
Mitelman databaseIGK/BCL2 [MCList]  IGK (14q32.33) BCL2 (18q21.33)
Other databaseBCL2/IGH translocation (18/14) (Bari)
REVIEW articlesautomatic search in PubMed
Last year articlesautomatic search in PubMed
All articlesautomatic search in PubMed

© Atlas of Genetics and Cytogenetics in Oncology and Haematology
indexed on : Wed Nov 28 16:19:34 CET 2018

Home   Genes   Leukemias   Solid Tumors   Cancer-Prone   Deep Insight   Case Reports   Journals  Portal   Teaching   

For comments and suggestions or contributions, please contact us