GNAS and progressive osseous heteroplasia: This is of relevance due to the fact that a mutation in GNAS has been shown to activate hedgehog signaling, which has been shown to cause cutaneous ossification in conditions such as progressive osseous heteroplasia (POH), osteoma cutis Albright hereditary osteodystrophy (AHO) (Adegbite et al., 2008; Elli et al., 2013; Regard et al., 2013).