| Clinics and Pathology |
| Disease | T- Acute lymphoblastic leukemia (T-ALL) |
| Phenotype / cell stem origin | T lineage TCR gamma delta +, CD4/8 double positive (DP), CD1a- immunophenotype |
| Epidemiology | 1 case reported |
| Clinics | FABL1 or L2. The index case had hepatosplenomegaly without mediastinal involvement. |
| Cytogenetics |
| Cytogenetics Molecular | Balanced t(7;14) |
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| Fig1: FISH hybridization result using a TCRA/D distal (Green) and HOXA proximal (orange) FISH probes showing a fusion signal in 6 of 8 mitosis. | |
| Additional anomalies | This case also expressed (by RQ-PCR) a CALM-AF10 fusion transcript (t(10;11)(p13;q14-21)). |
| Variants | variant translocation cases are reported: 9 cases of T-ALLs having the HOXA locus translocated to TCRB in a t(7;7). The breakpoints on 7p15 in those HOXA-TCRB cases are more centromeric, close to HOXA9 |
| Genes involved and Proteins |
| Gene Name | HOXA (intronic region) |
| Location | 7p15 |
| Note | HOXA6 and HOXA7 lie at 6,9kb from each other on 7p15 |
| Protein | various HOXA genes act as transcription factors playing important roles in the differentiation and commitment processes of embryonic and hematopoietic cells. |
| Gene Name | TCRD |
| Location | 14q11 |
| Note | Breakpoint on der(7) lie 5' from Jd1. Breakpoint on der(14)lies 12 nucleotides 5' of the 3' end of the DREC segment. |
| Protein | Protein encoded by the TCRD locus are the T-cell receptor chains. |
| Result of the chromosomal anomaly |
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| Fig2: Sequence of events leading to the final translocation. Exons are represented by boxes. Triangles represent RSS and show their orientation. E=enhancer. | |
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| Fig3: The nucleotide sequence of both derivatives implicated in the t(7 ;14) translocation. Underscored are RSS or RSS-like sequence in the vincinity of the breakpoints. In lower case letters: non templated nucleotides at the junction. | |
| Description | No fusion protein. Overexpression of HOXA genes as a result of the translocation with TCRD was expected, as it was demonstrated to be the case in HOXA-TCRB T-ALLs. However this case had a CALM-AF10 fusion in the same leukemic clone. CALM-AF10 is already known to be associated with HOXA cluster global overexpression. The HOXA pattern of expression in this case was similar to other CALM-AF10 T-ALL. |
| Oncogenesis | Probable, as several HOX/HOXA genes have been implicated in leukemic processes. |
| External links |
| Other database | t(7;14)(p15;q11) | Mitelman database (CGAP - NCBI) | |
| Other database | t(7;14)(p15;q11) | 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 |
| MLL translocations specify a distinct gene expression profile that distinguishes a unique leukemia. |
| Armstrong SA, Staunton JE, Silverman LB, Pieters R, den Boer ML, Minden MD, Sallan SE, Lander ES, Golub TR, Korsmeyer SJ |
| Nature genetics. 2002 ; 30 (1) : 41-47. |
| PMID 11731795 |
| V(D)J-mediated translocations in lymphoid neoplasms: a functional assessment of genomic instability by cryptic sites. |
| Marculescu R, Le T, Simon P, Jaeger U, Nadel B |
| The Journal of experimental medicine. 2002 ; 195 (1) : 85-98. |
| PMID 11781368 |
| MLL targets SET domain methyltransferase activity to Hox gene promoters. |
| Milne TA, Briggs SD, Brock HW, Martin ME, Gibbs D, Allis CD, Hess JL |
| Molecular cell. 2002 ; 10 (5) : 1107-1117. |
| PMID 12453418 |
| CALM-AF10 is a common fusion transcript in T-ALL and is specific to the TCRgammadelta lineage. |
| Asnafi V, Radford-Weiss I, Dastugue N, Bayle C, Leboeuf D, Charrin C, Garand R, Lafage-Pochitaloff M, Delabesse E, Buzyn A, Troussard X, Macintyre E |
| Blood. 2003 ; 102 (3) : 1000-1006. |
| PMID 12676784 |
| Age-related phenotypic and oncogenic differences in T-cell acute lymphoblastic leukemias may reflect thymic atrophy. |
| Asnafi V, Beldjord K, Libura M, Villarese P, Millien C, Ballerini P, Kuhlein E, Lafage-Pochitaloff M, Delabesse E, Bernard O, Macintyre E |
| Blood. 2004 ; 104 (13) : 4173-4180. |
| PMID 15054041 |
| CALM-AF10+ T-ALL expression profiles are characterized by overexpression of HOXA and BMI1 oncogenes. |
| Dik WA, Brahim W, Braun C, Asnafi V, Dastugue N, Bernard OA, van Dongen JJ, Langerak AW, Macintyre EA, Delabesse E |
| Leukemia : official journal of the Leukemia Society of America, Leukemia Research Fund, U.K. 2005 ; 19 (11) : 1948-1957. |
| PMID 16107895 |
| HOXA genes are included in genetic and biologic networks defining human acute T-cell leukemia (T-ALL). |
| Soulier J, Clappier E, Cayuela JM, Regnault A, Garcˆ‚a-Peydrˆ„ M, Dombret H, Baruchel A, Toribio ML, Sigaux F |
| Blood. 2005 ; 106 (1) : 274-286. |
| PMID 15774621 |
| A new recurrent inversion, inv(7)(p15q34), leads to transcriptional activation of HOXA10 and HOXA11 in a subset of T-cell acute lymphoblastic leukemias. |
| Speleman F, Cauwelier B, Dastugue N, Cools J, Verhasselt B, Poppe B, Van Roy N, Vandesompele J, Graux C, Uyttebroeck A, Boogaerts M, De Moerloose B, Benoit Y, Selleslag D, Billiet J, Robert A, Huguet F, Vandenberghe P, De Paepe A, Marynen P, Hagemeijer A |
| Leukemia : official journal of the Leukemia Society of America, Leukemia Research Fund, U.K. 2005 ; 19 (3) : 358-366. |
| PMID 15674412 |
| HOXA cluster deregulation in T-ALL associated with both a TCRD-HOXA and a CALM-AF10 chromosomal translocation. |
| Bergeron J, Clappier E, Cauwelier B, Dastugue N, Millien C, Delabesse E, Beldjord K, Speleman F, Soulier J, Macintyre E, Asnafi V |
| Leukemia : official journal of the Leukemia Society of America, Leukemia Research Fund, U.K. 2006 ; 20 (6) : 1184-1187. |
| PMID 16572206 |
| Contributor(s) |
| Written | 06-2006 | Julie Bergeron, Elizabeth Macintyre , Vahid Asnafi |
| Laboratoire d'Hématologie and INSERM EMI0210, Hôpital Necker-Enfants Malades, Université Paris-Descartes, AP-HP, Paris, France |
| Citation |
| This paper should be referenced as such : |
| Bergeron J, Macintyre E, Asnafi V . t(7;14)(p15;q11). Atlas Genet Cytogenet Oncol Haematol. June 2006 . URL : http://AtlasGeneticsOncology.org/Genes/t0714p15q11ID1435.html |
| © Atlas of Genetics and Cytogenetics in Oncology and Haematology | indexed on : Wed Sep 24 21:06:57 2008 |
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