Genetic Diseases, Inborn

• Connecticut Children's Medical Center — Hartford, Connecticut, United States
• Hôpital Antoine Béclère — Clamart, France
• Universitair Medisch Centrum Groningen — Groningen, Netherlands
• National Hospital for Neurology and Neurosurgery — London, Greater London, United Kingdom

• Royal Victoria Hospital — Belfast, United Kingdom
• Birmingham Children's Hospital — Birmingham, United Kingdom
• Northern General Hospital — Sheffield, United Kingdom

• NHS Greater Glasgow and Clyde — Glasgow, Lanarkshire, United Kingdom
• Birmingham Women's and Children's NHS Foundation Trust — Burringham, West Midlands, United Kingdom
• Bradford Teaching Hospitals NHS Foundation Trust — Bradford, West Yorkshire, United Kingdom

• NHS Greater Glasgow and Clyde — Glasgow, Lanarkshire, United Kingdom
• Birmingham Children's Hospital NHS Foundation Trust — Birmingham, West Midlands, United Kingdom
• Bradford Teaching Hospitals NHS Foundation Trust — Bradford, West Yorkshire, United Kingdom

• National Alkaptonuria Centre, Royal Liverpool University Hospital — Liverpool, Merseyside, United Kingdom
• Birmingham Children's Hospital — Birmingham, West Midlands, United Kingdom

• Xlab, Faculty of Health and Medical Sciences, University of Copenhagen — Copenhagen, Denmark

• Investigational Site Italy — Italy

• POTS Care — Colleyville, Texas, United States

Not specified

• National Institutes of Health Clinical Center — Bethesda, Maryland, United States