FP reports Advisory Board Membership and Lectures for Ultragenyx. PP reports Research Grants from Amgen, Ultragenyx, and Shire, and employment by Ascendis Pharma, Inc. SHR reports support from Ultragenyx, Kyowa Kirin, Lilly, and Amgen/UCB for enrolling patients into clinical trials, and non-financial support from Eli Lilly. YT reports Personal Fees from Kyowa Hakko Kirin Co. Ltd., and Grants and Personal Fees from Chugai Pharmaceutical Co. Ltd. and Teijin Pharma Ltd. TJW reports Research Support, Travel Fees, and Honoraria from Ultragenyx Pharmaceutical, Inc. LZ, CTO, MM, and JSM were employees and stockholders of Ultragenyx Pharmaceutical, Inc. during the study.