I have briefly outlined the PKU program in the State of Virginia and tried to demonstrate how this screening experience has disclosed the heterogeneity of the disease plus the need for an individualized approach to dietary control. I have applied the principles of mass screening to examine the feasibility of testing for other inborn errors and, on this basis, feel that galactosemia will soon next join with PKU. Mass screening for other aminoacidopathies will await more refined testing techniques and a definition of their incidence and mode of therapy. In the meantime, accumulated experience thus far mandates the establishment of specialized lab facilities and multidisciplinary teams; these will be necessary to effect optimal evaluation and treatment of patients found to be positive by these screening techniques
