RESUMEN
Starting from an international overview of the current status of screening programs, the present paper focuses on the legal situation in Italy and the great differences among Italian regions. Since the introduction of tandem mass spectrometry (MS/MS) in the 90s the paradigm one spot-one disease changed. Only recently, some regions issued legislative acts to promote expanded newborn screening with MS/MS. This approach raises medico-legal and ethical issues because a fast neonatal diagnosis of an inborn error of metabolism (IEM) could increase chances of an early treatment and reduce disabilities, therefore citizens ought to have the same access to care countrywide. Enacting a mandatory standard for a disease screening panel using MS/MS and a few centers specialized in diagnosis, treatment and follow-up of patients affected by IEM (inborn errors of metabolism) can reduce legal and ethical issues.