Neonatal diagnosis of severe combined immunodeficiency leads to significantly improved survival outcome: the case for newborn screening.

Severe combined immunodeficiency (SCID) carries a poor prognosis without definitive treatment by hematopoietic stem cell transplantation. The outcome for transplantation varies and is dependent on donor status and the condition of the child at the time of transplantation. Diagnosis at birth may allow for better protection of SCID babies from infection and improve transplantation outcome. In this comparative study conducted at the 2 designated SCID transplantation centers in the United Kingdom, we show that SCID babies diagnosed at birth because of a positive family history have a significantly improved outcome compared with the first presenting family member. The overall improved survival of more than 90% is related to a reduced rate of infection and significantly improved transplantation outcome irrespective of donor choice, conditioning regimen used, and underlying genetic diagnosis. Neonatal screening for SCID would significantly improve the outcome in this otherwise potentially devastating condition.