Sir.—A 16-month-old American boy, born outside the United States, when seen for routine care presented with signs of delayed development. He had not had a newborn screening test and he had phenylketonuria (PKU). This case suggests there is a need to screen American children born outside the United States for PKU when they return if they do not have documented negative test results. Routine screening should be done of those children younger than 1 year, regardless of development, and after 1 year of age if their development is not appropriate. Parents should be urged to have screening tests done if they live outside the country. Newborn screening results should be part of the immunization records.
Early detection and screening for PKU became widely accepted in the mid-1960s in the United States.1 States vary with regard to conditions and the timing for screening. The American Academy of Pediatrics Committee