SP7 and skeletal dysplasia: Other SP7 point mutations (1502delA, E340A, and S309W) have been associated with distinct skeletal dysplasia in humans.17,18,35,36 Notably, the S309W human mutation, a change at a site adjacent to the R316C residue studied here, causes a distinct phenotype associated with dysregulated osteoblast maturation and a shifted DNA binding profile.36 Thus, defining the impact of the R316C mutation on DNA binding patterns across the genome represents an important priority.