COL1A2 and osteogenesis imperfecta: The osteogenesis imperfecta brittle bone phenotype, and the genetic association of collagen (I) homotrimer with osteoporosis (Mann et al., 2001; Ralston et al., 2006), contrasts with the phenotype of human patients in whom mutations leading to nonsense-mediated decay of the COL1A2 mRNA cause a specific cardiac valvular form of Ehlers-Danlos syndrome (EDS) (cvEDS), not involving bone (Guarnieri et al., 2019; Malfait et al., 2006), and evidence that Col1a2 silencing does not affect in vitro osteoblast mineralisation (Maruelli et al., 2020).