1. Growth and Development Laboratory, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania and Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
2. Department of Molecular Genetics and Biochemistry, University of Pittsburgh, Pittsburgh, Pennsylvania
3. Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
4. Growth and Development Laboratory, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania; Department of Orthopaedic Surgery and Department of Molecular Genetics and Biochemistry, University of Pittsburgh, Pittsburgh, Pennsylvania