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| | TRA/TRD
V-GENE: Green box: Functional; Red: Pseudogene.
D-GENE: Blue: Functional.
J-GENE: Yellow: Functional; Pale yellow: Open reading frame; Red: pseudogene.
C-GENE: Blue: Functional.
for complete Figure, see: locus TRA, IMGT (The International ImMunoGeneTics information system ®) © Copyright 1995-2003 IMGT, IMGT is a CNRS trademark |
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| Description | The human TRA locus at 14q11.2 spans 1000 kilobases (kb). It consists of 54 TRAV genes belonging to 41 subgroups, 61 TRAJ segments localized on 71 kb, and a unique TRAC gene. The most 5' TRAV genes occupy the most centromeric position, whereas the TRAC genes, 3' of the locus, is the most telomeric gene in the TRA locus. The organization of the TRAJ segments on a large area is quite unusual and has not been observed in the other immunoglobulin or T cell receptor loci. Moreover the TRD locus is nestled in the TRA locus between the TRAV and TRAJ segments. V-J-rearrangements in the TRA locus therefore result in deletion of the TRD genes localized on the same chromosome. That deletion occurs in two steps, that is a deletion of the TRD genes, involving specific sequences located upstream from TRDC (sequence pseudo J alpha) would take place before the TRAV-J rearrangement. The potentiel genomic TRA repertoire comprises 45-47 functional TRAV genes belonging to 33-35 subgroups, 50 functional TRAJ segments, and the unique TRAC gene. Among the variable genes are included five genes designated as TRAV/DV which belong to five different subgroups and which have been found rearranged either to TRAJ or to TRDD segments and can therefore be used in the synthesis of alpha or delta chains. The total number of human TRA genes per haploid genome is 116 of which 96 to 98 genes are functional. Enhancer sequences have been characterized 4.5kb 3' from TRAC. List of the human TRA genes |
| Entity | Translocations which frequently result from errors of the recombinase enzyme complex (RAG1, RAG2, etc.), which is responsable of the Immunoglobulin and T cell receptor V-J and V-D-J rearrangements. TRAV or TRAJ recombination signals or isolated heptamer are observed at the breakpoints. |
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| Entity | t(1;14)(p32;q11); involve TAL1 in 1p32 |
| Prognosis | median survival > 5 yrs in children |
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| Entity | t(8;14)(q24;q11); involve MYC in 8q24 |
| Disease | T-cell acute lymphocytic leukemia (ALL); rare |
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| Entity | t(10;14)(q24;q11); involve HOX11 in 10q24 |
| Disease | T- cell acute lymphoblastic leukemia (ALL) and non-Hodgkin lymphoma (NHL) |
| Prognosis | not unfavourable |
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| Entity | t(11;14)(p13;q11); involve RBTN2 in 11p13 |
| Disease | T-cell acute lymphocytic leukemia (ALL) |
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| Entity | t(14;14)(q11;q32), inv(14)(q11q32); involve TCL1 in 14q32 |
| Disease | T-cell prolymphocytic leukemia (T-PLL) and adult T cell leukemia/lymphoma |
| Prognosis | poor |
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| Entity | t(14;21)(q11;q22); involve OLIG2 in 21q22 |
| Disease | T-cell acute lymphoblastic leukemia (ALL) |
| Prognosis | unknown |
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| Crystal structure of p14TCL1, an oncogene product involved in T-cell prolymphocytic leukemia, reveals a novel beta-barrel topology. |
| Hoh F, Yang YS, Guignard L, Padilla A, Stern MH, Lhoste JM, van Tilbeurgh H |
| Structure (London, England : 1993). 1998 ; 6 (2) : 147-155. |
| PMID 9519406 |
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| Nomenclature of the human T cell Receptor genes (Review) |
| Lefranc MP |
| Current Protocols in Immunology. 2000. |
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| The T cell Receptor FactsBook (Review) |
| Lefranc MP and Lefranc G |
| Academic Press, London, UK (. 1939. |
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| Locus Map and Genomic repertoire of the Human Immunoglobulin Genes (Review) |
| Lefranc MP |
| The immunologist,. 2000. |
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