Authors' Disclosures or Potential Conflicts of Interest: Upon manuscript submission, all authors completed the author disclosure form. Disclosures and/or potential conflicts of interest:
Employment or Leadership: D.L. Marsden, Ultragenyx Pharma.
Consultant or Advisory Role: O.A. Bodamer, PerkinElmer; M.E. Gelb, PerkinElmer; D.S. Millington, Babies, Inc.; F.A. Wijburg, MPS I International Registry and BioMarin MPS IV diagnosis ad board.
Stock Ownership: D.L. Marsden, Ultragenyx Pharma; D.S. Millington, Babies, Inc.
Honoraria: F.A. Wijburg, Genzyme Sanofi, BioMarin, and Shire.
Expert Testimony: F.A. Wijburg, Dutch Health Council on Newborn Screening.
Patents: None declared.
Other Remuneration: O.A. Bodamer, Genzyme-Sanofi.