Development of a routine newborn screening protocol for severe combined immunodeficiency. J Allergy Clin Immunol 2009 Sep;124(3):522-7
Date
06/02/2009Pubmed ID
19482345DOI
10.1016/j.jaci.2009.04.007Scopus ID
2-s2.0-69349101950 (requires institutional sign-in at Scopus site) 151 CitationsAbstract
BACKGROUND: Severe combined immunodeficiency (SCID) is characterized by the absence of functional T cells and B cells. Without early diagnosis and treatment, infants with SCID die from severe infections within the first year of life.
OBJECTIVE: To determined the feasibility of detecting SCID in newborns by quantitating T-cell receptor excision circles (TRECs) from dried blood spots (DBSs) on newborn screening (NBS) cards.
METHODS: DNA was extracted from DBSs on deidentified NBS cards, and real-time quantitative PCR (RT-qPCR) was used to determine the number of TRECs. Positive controls consisted of DBS from a 1-week-old T(-)B(-)NK(+) patient with SCID and whole blood specimens selectively depleted of naive T cells.
RESULTS: The mean and median numbers of TRECs from 5766 deidentified DBSs were 827 and 708, respectively, per 3.2-mm punch ( approximately 3 muL whole blood). Ten samples failed to amplify TRECs on initial analysis; all but 1 demonstrated normal TRECs and beta-actin amplification on retesting. No TRECs were detected in either the SCID or naive T-cell-depleted samples, despite the presence of normal levels of beta-actin.
CONCLUSIONS: The use of RT-qPCR to quantitate TRECs from DNA extracted from newborn DBSs is a highly sensitive and specific screening test for SCID. This assay is currently being used in Wisconsin for routine screening infants for SCID.
Author List
Baker MW, Grossman WJ, Laessig RH, Hoffman GL, Brokopp CD, Kurtycz DF, Cogley MF, Litsheim TJ, Katcher ML, Routes JMMESH terms used to index this publication - Major topics in bold
ActinsDNA
Humans
Infant, Newborn
Neonatal Screening
Polymerase Chain Reaction
Receptors, Antigen, T-Cell
Reproducibility of Results
Severe Combined Immunodeficiency
