The TRD locus is embedded in the TRA locus, between the TRAV and TRAJ genes (for detailed references, see ).
The orientation of the human TRA and TRD loci on the chromosome is forward (FWD).
The orientation of the locus has been determined by the analysis of translocations, involving the TRA and TRD loci, in leukemia and lymphoma.
A vertical red line indicates the localization of the TRA and TRD loci at
A blue arrow indicates the orientation 5' → 3' of the loci, and the gene group order in the loci. Note that the TRDV gene localized in 3' of the TRDC gene is in inverted orientation of transcription (shown by a small black arrow). The blue arrow is proportional to the total size of the loci, indicated in kilobases (kb). The total number of genes in the TRA and TRD loci is shown between parentheses.