Why should TREC and KREC quantification assay be concerned to screen of newborns in developing countries?

Document Type: Review


Department of Microbiology and Immunology, Faculty of Medicine, Kashan University of Medical Sciences, Kashan, Iran; Department of Infectious Disease and Immunology, College of Veterinary Medicine, University of Florida, FL, USA.



Primary immunodeficiencies contain a group of several different diseases. Giving the fact that their clinical outcome ranges from mild to potentially life-threatening,
detection of patients with these diseases in the neonatal period is the main goal of efforts is currently being made. It has been reported that T-cell receptor excision circles (TRECs) and kappa-deleting recombination excision circles (KRECs) are circular DNA segments produced in T and B cells during their maturation in the thymus and bone marrow, respectively. Fortunately, excision circles can be reliably quantified using real-time quantitative PCR techniques. The TREC and KREC assays, introduced in the newborn screening program (NBS), allow early disease identification and may lead to discovery of new genetic defects including Severe combined immunodeficiencies (SCID), primary agammaglobulinaemias (such as X-linked agammaglobulinaemia) and inherited haemophagocytic syndromes (such as familial haemophagocytic lymphohistiocytosis). In this regard, the cost-effectiveness, survival of children and successful in improving quality of life children involved in newborn screenings for severe combined immunodeficiencyand has been demonstrated.
Here we discuss about TREC and KREC assay, their applications and also assessment of the cost effective of establishment of a program for newborn screening based on TRECs and KRECs quantification in Iran.