The TRG (T cell receptor gamma locus) gene is located on chromosome 7 (7p15) and encodes components of the gamma chain of the T cell receptor complex 1. The TRG locus consists of 2 constant region genes (TRGC), 5 joining segments (TRGJ), and at least 14 variable gamma genes (TRGV), with 8 functional variable genes belonging to 4 different subgroups 1. The gene undergoes V(D)J recombination specifically in T cells, similar to other T cell receptor genes 1. The rearranged TRG gene produces the gamma chain polypeptide, which is expressed on the surface of a subset of CD3+CD4-CD8- T lymphocytes that lack the conventional alpha-beta T cell receptor 1. These gamma-delta T cells display cytolytic activity, though their precise immunological function remains incompletely understood 1. TRG mutations have been identified in approximately 30% of familial interstitial lung disease cases, where they are associated with telomere dysfunction and can cause both pulmonary fibrosis and extra-pulmonary manifestations including immune-hematological, hepatic, and mucocutaneous symptoms 2. Patients with TRG mutations may experience accelerated disease progression and require genetic counseling 2.