Genetic screening of newborns

Screening of newborn infants for genetic disease began over 35 years ago as a public health measure to prevent mental retardation in phenylketonuria ( PKU). It was so successful that tests for several other genetic disorders w ere added. We review the current status of this screening, including discus sions of the genetic disorders often covered and the results of newborn scr eening for them. We emphasize recent advances. These include expansion of c overage for genetic disorders with the new methodology of tandem mass spect rometry (MS-MS) and the introduction of molecular (DNA) testing to increase the specificity of testing for several disorders, thereby reducing false-p ositive rates. These and other advances have also produced issues of criter ia for screening, missed cases, and appropriate use of stored newborn speci mens.