Issues in newborn screening.

Newborn screening aims at the earliest possible recognition of disorders so that intervention with effective treatment can prevent the most serious consequences of the disorder. However, of several thousand known genetic disorders, therapy is presently available for only a small proportion of them. Newborn screening was first applied to phenylketonuria (PKU). Presently, newborn screening programs have been implemented in 26 countries for different diseases. However, potential problems in newborn screening programs that make implementation of newborn screening programs difficult include quality assessment, concerns about professional and technical competence, and ethical considerations. It has been shown that in the process from sampling the newborn to reporting of the screening results most errors are made in the pre- and post-analytical phases. It appears that much more could be done for the fetus if genetic screening and diagnostics could be accomplished early in pregnancy rather than after birth.