While our functional studies focused on genes uniquely associated with variation in skull BMD, there are plenty of genes implicated in craniosynostosis (e.g., EN1, RUNX2, SOX6, BMP2, JAG1, LRP5, IDUA30,44,47,48) across the whole set of identified BMD loci (Supplementary Table 1). Here, SOX6 is linked to craniosynostosis.