1 Children's Hospital Medical Center, Boston, Massachusetts 02115
WHEN the concept of mass screening of newborns for phenylalaninemia was first proposed, many voices were raised in protest. Chief among the objections listed was the impracticability of searching for a disease so rare that only one such infant would be found in 20,000 tested.
Today, mass screening for phenylalaninemia is a fact rather than a concept, but the storm of controversy has increased rather than subsided. There is, however, no longer any argument about the practicability of mass screening; the techniques used have proved eminently successful, in part helped by the finding that the incidence of presumptive PKU is now believed to be one in 10,000 or nearly double the earlier estimate.