TREC Screening for WHIM Syndrome.

Purpose: T cell receptor excision circle (TREC) quantification is a recent addition to newborn screening (NBS) programs and is intended to identify infants with severe combined immunodeficiencies (SCID). However, other primary immunodeficiency diseases (PID) have also been identified as the result of TREC screening. We recently reported a newborn with a low TREC level on day 1 of life who was diagnosed with WHIM (warts, hypogammaglobulinemia, infections, myelokathexis) syndrome, a non-SCID primary immunodeficiency caused by mutations in the chemokine receptor CXCR4.