Newborn screening: an overview.

The ethical considerations and the criteria for inclusion of a test to a newborn screening program have remained constant since testing began in the 1960s. Does the test identify a treatable disorder with significant incidence to pose a public health risk and warrant testing all babies in that state or territory? Technological advances in testing, particularly with the improvement of tandem mass spectrometry techniques and the advent of DNA testing for the specific gene mutations, have expanded our understanding of many inherited metabolic diseases. These mostly autosomal recessive disorders went under-diagnosed by the medical community for many years. This was partly due to the notion that the incidence of inherited metabolic diseases was quite rare and that many so-called birth defects, or unexplained infant deaths, were not associated with any known metabolic disorders. Public health departments, as part of their newborn health programs, offer some newborn screening to all infants born within their jurisdiction. Two tests, those for phenylketonuria (PKU) and congenital hypothyroidism are universally mandated (51/51 juristictions). The next highest frequency tests are for galactosemia and sickle cell disease (50/51), with up to thirty tests available in some states. However, the authority as to which tests are included resides with the local state government, either as a matter of law or as a matter for the public health department. As these matters become more complex, many public health officials and pediatric healthcare practitioners urge the Federal government to become involved and develop national guidelines in an effort to streamline the process and decrease the existing inconsistencies between states. For many laboratorians, the collection of newborn screening blood spot samples is the extent of their involvement in newborn screening programs. The many facets of these programs, the status of newborn screening in the United States, and the incidence and description of selected inherited disorders are explored.