Management of newborn screening for severe combined immunodeficiency at a quaternary referral centre – an updated algorithm

Severe combined immunodeficiency is caused by critical genetic defects affecting the immune system. Early diagnosis and intervention are essential for preventing life-threatening infections, end-organ damage, and complications. Newborn screening for severe combined immunodeficiency is currently rolled out across many provinces and territories across Canada. The SickKids Newborn Screening Centre in Toronto, Ontario, is a quaternary referral centre that has evaluated SCID newborn screen-positive infants since the program’s introduction in 2013. Here, we provide updated algorithms for clinical investigation and follow-up of infants with an initial positive screen.