1. Greenberg Center for Skeletal Dysplasias, McKusick-Nathans Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland;
2. Nemours/Alfred I. duPont Hospital for Children and Sidney Kimmel Medical College, Thomas Jefferson University, Wilmington, Delaware; and
3. Department of Pediatrics, University of California, San Diego and Rady Children’s Hospital, San Diego, California