T-cell receptor excision circle
Also written as: TREC — T-cell receptor excision circle
Circular DNA fragments generated during T-cell receptor gene rearrangement, used as markers of recent thymic T-cell production.
Full Definition
Stable circular DNA molecules formed as byproducts of V(D)J recombination during T-cell development in the thymus. T-cell receptor excision circles (TRECs) serve as reliable biomarkers for recent thymic output because they are not replicated during cell division and are diluted as T cells proliferate peripherally. TREC quantification by PCR has become a standard component of newborn screening programs for severe combined immunodeficiency and is used to monitor thymic function in various clinical contexts. Low or absent TREC levels indicate impaired thymic T-cell production, while normal levels suggest adequate thymic function.
Usage
Usage note: Often abbreviated as TREC; distinguish from KRECs (kappa-deleting recombination excision circles).
In Context
- "Undetectable T-cell receptor excision circles on newborn screening prompted urgent immunological evaluation." — Pediatric immunology referral
- "T-cell receptor excision circle levels normalized following successful thymic transplantation." — Post-transplant monitoring report