Test reliably detects inherited immune deficiency in newborns

A newborn screening test for severe combined immunodeficiency (SCID) reliably identifies infants with this life-threatening inherited condition, leading to prompt treatment and high survival rates, according to a study supported by the National Institutes of Health. Researchers led by Jennifer Puck, M.D., of the University of California, San Francisco, also found that SCID affects approximately 1 in 58,000 newborns, indicating that the disorder is less rare than previously thought. The study was funded in part by NIH’s National Institute of Allergy and Infectious Diseases (NIAID) and Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD).

SCID is a group of disorders caused by defects in genes involved in the development and function of T cells and other infection-fighting immune cells. Infants with SCID are highly susceptible to life-threatening infections. SCID is fatal, usually within the first year or two of life, unless affected infants are given immune-restoring treatments such as transplants of blood-forming stem cells or gene therapy. More than 80 percent of affected infants do not have a family history of the condition.

“The results of this study highlight the important role of newborn screening for SCID,” said NIAID Director Anthony S. Fauci, M.D. “The findings demonstrate that detecting SCID before symptoms such as severe infections appear helps ensure that infants with this serious condition receive lifesaving treatments.”

The SCID newborn screening test, originally developed at NIH, measures T cell receptor excision circles (TRECs), a by-product of T-cell development. Infants with SCID have few or no T cells, regardless of the underlying genetic defect, and the absence of TRECs may indicate SCID. The TREC test also may help doctors identify infants with non-SCID T-cell deficiencies. SCID was added in 2010 to the U.S. Department of Health and Human Services’ Recommended Uniform Screening Panel for newborns in the United States. However, the TREC test has not yet been adopted universally. Nearly half of states conduct newborn screening for SCID, and the test is performed for almost two thirds of infants born across the country.

“We have made great strides in our knowledge of SCID and other related immunodeficiencies in a relatively short period of time, thanks to newborn screening,” said Tiina Urv, Ph.D., a program director in the Intellectual and Developmental Disabilities Branch at NICHD. “Such collaborative research efforts could serve as a model for other disorders.” Eunice Kennedy Shriver National Institute of Child Health and Human Development