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. Author manuscript; available in PMC: 2015 Jun 19.
Published in final edited form as: Ann N Y Acad Sci. 2011 Dec;1246:108–117. doi: 10.1111/j.1749-6632.2011.06346.x

Table 3.

Summary of California TREC screening experience in the first year

  • 507,000 births screened

  • DNA amplification failures (DAF), <0.08%, requiring second heelsticka

    • Comparable to other newborn screening assays

    • 56% were <1,500 g at birth

    • 44% had first sample drawn from an indwelling catheter, not a heelstick

    • 84% were in neonatal intensive care units at time of collection

  • 50 positive tests, 0.01% of births, required CBC and lymphocyte flow cytometry

  • 20 follow-up liquid blood samples, 40%, had low T cells confirmed by CBC and flow cytometry

  • Diagnoses made:

    • 6 SCIDb

      • 2 IL-7RA

      • 2 RAG1

      • 2 Common γ-chain

    • 1 Omenn syndromec due to missense mutations of RAG2

    • 3 SCID variant with no known gene defect

    • 4 Syndromes with T lymphocytopenia

      • 3 DiGeorge (1 complete)

      • 1 Trisomy 21

    • 6 Secondary T lymphocytopenia

      • 2 Gastroschesis

      • 1 Gastrointestinal atresia

      • 3 Prematurity

a

Since all non-SCID screening is done first in regional labs, with samples then forwarded to a central lab for TREC testing, most newborns were two weeks old when the TREC result was available. When a SCID-specific repeat heelstick was needed, older age usually resulted in a normal TREC value on redraw.

b

Only one SCID case had a positive family history leading to testing at birth.

c

Signs of Omenn syndrome in the first weeks of life had led to the diagnosis just before the TREC test was reported.