The Political History of PKU: Reflections on 50 Years of Newborn Screening

* Abbreviations: NBS — : newborn screening PKU — : phenylketonuria Just over 50 years ago, Dr Robert Guthrie developed a simple screening test for phenylketonuria (PKU) that became the prototype for universal newborn screening programs. Historians Jeffrey Brosco and Diane Paul explore why PKU screening marked a historical turning point in public health. It is a story that has left a far more complex legacy than most pediatricians recognize.—Jeffrey P. BakerSection Editor, Historical Perspectives Phenylketonuria, or PKU as it is more familiarly known, is a rare disorder, affecting only ∼1 in 15 000 people. In the United States, for example, ∼275 infants will be born with the disease each year.1 Thus in a lifetime of practice most pediatricians will not encounter a single case. Yet probably every pediatrician in the industrialized world has learned about PKU during medical school, many parents vividly remember the heel-stick test for their newborn, and scientists interested in genetics and metabolism say that they hope to “find another PKU.” Why has such a rare condition garnered so much attention? PKU is famous in part because it is widely seen as a victory for scientific medicine. If the condition is detected in the newborn period and a specialized diet is instituted, the profound cognitive impairment usually caused by PKU is averted. For the diet to be effective, however, the otherwise normal-appearing infant with PKU must be identified, among thousands of other nonaffected infants, in the first weeks of life. In the early 1960s, parents of children with intellectual disability began to advocate for state laws to test all newborns in the United States, and the first state laws for universal newborn screening (NBS) were implemented 50 years ago. By 1965, 32 American states had enacted screening laws, all but 5 making the test compulsory. By the mid-1970s, NBS for PKU had become routine in … Address correspondence to Jeffrey P. Brosco, MD, PhD, Department of Pediatrics, University of Miami Miller School of Medicine, PO Box 016820, Miami, FL 33101. E-mail: jbrosco{at}miami.edu