Diagnostic guidelines for newborns who screen positive in newborn screening.

BACKGROUND: Recent expansion of the newborn screening panels has presented an interesting challenge to specialty care centers, especially the clinical genetics community. Some of the conditions in the core and secondary newborn screening panels have extremely variable clinical presentations; others are so rare that only a handful of newborns have been diagnosed with them to date (Region 4 Collaborative MS/MS project-http://region4genetics.org/msms_data_project/data_project_home.aspx). Definition of some disorders is problematic-does continued abnormality of the screening analyte constitute diagnosis or is further testing necessary? METHODS: A work group of the New York Mid-Atlantic Consortium for Genetic and Newborn Screening Services (region 2), one of seven regional collaboratives funded by the Federal Health Resources and Services Administration and administered by the Maternal and Child Health Bureau (U22MC03956), has developed guidelines for the confirmation of diagnosis of the conditions in the newborn screening panels for use by the specialty care centers. DISCUSSION: The diagnostic guidelines are a work in progress and are being reviewed and revised regularly as our understanding of the newborn screened disorders improves. The aim is to make it a relevant guide for specialty care physicians and other healthcare professionals in the diagnostic workup of these patients.