1. Center for Medical Genetics, Ghent University Hospital (L.D., O.M.V.), Ghent University, Belgium.
2. Department of Biomolecular Medicine (L.D., O.M.V.), Ghent University, Belgium.
3. Ghent Ectopic Mineralization Research Group (L.D., O.M.V.).
4. Department of General Pediatrics, Münster University Children’s Hospital, Germany (Y.N., F.R.).