t(7;14)(q34;q11) TRA/TRB

2017-11-01   Adriana Zamecnikova , Adriana Zamecnikova 

1.Kuwait Cancer Control Center, Kuwait annaadria@yahoo.com

Abstract

Translocations and inversions involving the TRA/TRD locus at 14q11.2 and the TRB locus at 7q34 are characteristic anomalies in T-cell acute leukemia/lymphoma. In most instances, juxtaposing promoter and enhancer elements of TCR genes in the proximity of a partner gene results in their dysregulation that may be a critical step toward development of T-cell malignancies.

Clinics and Pathology

Noted

As translocation breakpoints near terminal regions of chromosomes are difficult to ascertain, included are cases with 7q35 breakpoints, probably involving TRB.

Etiology

T-cell malignancies: 4 patients with T-cell acute lymphoblastic leukemia (Kaneko et al., 1988; Secker-Walker et al., 1992; Cauwelier et al., 2006) and 3 with angioimmunoblastic T-cell lymphoma (AITL) (Cosimi et al., 1990) (Table 1.).
Table 1. Clinical and genetic testing findings in reported patients with t(7;14)(q34-36;q11).
 Sex/AgeDiagnosisKaryotype/td>
1M/14T-ALL46,XY,t(7;14)(q35;q11) 
2F/18T-ALL46,XX,t(7;14)(q34;q11)
330/MT-ALL46-47,XY,+der(14)t(7;14)(q34;q11),+mar1   TRA-TRD/TRB
4F/5T-ALL45,X,?der(X),t(7;14)(q34;q11),-9,-9,del(11)(p11),del(12)(p?13),+mar   TRA-TRD/TRB
5FAITL46,XX,dup(7)(q11q35),t(7;14)(q35;q11),t(7;7)(p13;q35)   LN
6FAITL46,XX,dup(7)(q11q35),t(7;14)(q35;q11),t(7;14)(p13;q11),add(14)(q11)   LN
7FAITL48,XX,+3,+7,t(7;14)(q35;q11),t(7;14)(p13;q11),t(14;14)(q11;q32)   LN

1. Kaneko et al., 1988; 2. Secker-Walker et al., 1992; 3-4. Cauwelier et al., 2006; 5-7. Cosimi et al., 1990.
Abbreviations: M, male; F, female; AITL, Angioimmunoblastic T-cell lymphoma; LN, lymph node; T-ALL, T-cell Acute lymphoblastic leukemia.

Epidemiology

2 female and 1 male patients aged 5, 18 and 30 years old (Secker-Walker et al., 1992; Cauwelier et al., 2006). In addition 1 male (Kaneko et al., 1988) and 3 female patients (Cosimi et al., 1990) with 7q35 breakpoints were reported.

Prognosis

Unknown due to the rarity of reported patients.

Genes Involved and Proteins

Gene name
TRB (T-cell receptor beta locus)
Location
7q34
Note
Various genes are activated in T-cell malignancies as a consequence of chromosome translocations, inversions and cryptic chromosomal rearrangements involving sequences from the TRB locus such as: t(6;7)(q27;q34) TRB/ MYB, inv(7)(p15q34)/t(7;7)(p15;q34) TRB/ HOXA10, t(7;9)(q34;q34) TRB/ NOTCH1, t(7;10)(q34;q24) TRB/ HOXA11, t(7;11)(q34;p15) TRB/ LMO1, t(7;11)(q34;p13) TRB/ LMO2, t(7;14)(q34;q32.1) TRB/ TCL1A.
Gene name
Location
14q11.2
Note
TRA/TRD is a target of chromosomal translocations and inversions including: inv(14)(q11q32.1)/t(14;14)(q11;q32.1) TRA-TRD/TCL1A, t(8;14)(q24.1;q11.2) MYC/TRA-TRD, t(10;14)(q24;q11.2) TLX1/TRA-TRD, t(11;14)(p15;q11.2) LMO1/TRA-TRD and t(11;14)(p13;q11.2) LMO2/TRA-TRD.

Result of the Chromosomal Anomaly

Oncogenesis

Translocations between T-cell receptor genes and various oncogenes are a genetic hallmarks of T-cell malignancies. Chromosomal aberrations affecting TCR gene loci mainly involve TRA/TRD at 14q11.2 and TRB at 7q34 and affect various known oncogenes that most often code for transcription factors or proteins involved in transcriptional complexes, the deregulated expression of which is putatively implicated in T-cell oncogenesis.

Bibliography

Pubmed IDLast YearTitleAuthors
166730212006Molecular cytogenetic study of 126 unselected T-ALL cases reveals high incidence of TCRbeta locus rearrangements and putative new T-cell oncogenes.Cauwelier B et al
22841411990Rearrangements on chromosomes 7 and 14 with breakpoints at 7q35 and 14q11 in angioimmunoblastic lymphadenopathy and IBL-like T-cell lymphoma.Cosimi MF et al
29000301988Chromosome translocations involving band 7q35 or 7p15 in childhood T-cell leukemia/lymphoma.Kaneko Y et al
13770081992Karyotype and T-cell receptor expression in T-lineage acute lymphoblastic leukemia.Secker-Walker LM et al

Summary

Fusion gene

TRA/TRB
Atlas Image
Figure 1. Partial karyotype with t(7;14)(q34;q11).

Citation

Adriana Zamecnikova ; Adriana Zamecnikova

t(7;14)(q34;q11) TRA/TRB

Atlas Genet Cytogenet Oncol Haematol. 2017-11-01

Online version: http://atlasgeneticsoncology.org/haematological/3284/t(7;14)(q34;q11)-tra-trb

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