Newborn screening programs: should 22q11 deletion syndrome be added?

The highly variable 22q11 deletion syndrome has been proposed for addition to newborn screening panels. A literature review investigated the incidence and prevalence, clinical features, and prognosis of 22q11 deletion syndrome and other issues related to newborn screening. Severe complications that could potentially be helped by screening include cardiac defects in 80% (with 20% having no outward signs to aid detection), hypocalcemia that can lead to seizures in 20% (though hypocalcemia is routinely investigated in sick newborns), and severe immune deficiency in <1% (which would be identified by some states' severe combined immunodeficiency screens). Other benefits that do not fit traditional goals of newborn screening include treatment for complications such as failure to thrive and developmental delay or preventing a "diagnostic odyssey." Although universal screening may prove the incidence to be >1:5000, undetected life-threatening effects occur in a minority of 22q11 deletion syndrome patients. Concerns include an untested screening technique, difficulty obtaining results in time for cardiac intervention, the chance of "vulnerable child syndrome" in mild cases, and possibly detecting congenital heart disease more efficiently by other means. Because addition of tests for highly variable conditions such as 22q11 deletion syndrome is likely to set a precedent for other syndromes, reevaluation of newborn screening criteria should be considered.