HCH (OMIM 14600) is a mild-to-severe form20,21 of chondrodysplasia – an autosomal dominant disorder characterized by disproportionately short stature, short limbs, macrocephaly, frontal bossing, midfacial retrusion, and relative prognathism.22,23 With a view to characterizing the processes involved in mandible formation, researchers have developed a number of mouse models expressing the Fgfr2 and Fgfr3 gain-of-function mutations associated with craniosynostosis or chondrodysplasia. The gene discussed is FGFR2; the disease is chondrodysplasia.