For instance, in one case with COL1A2‐related severe perinatal form of Osteogenesis imperfecta (OI) (Sillence type 2), US showed shortening and bowing of the long bones indicating skeletal dysplasia, but femoral fractures and multiple rib fractures diagnostic to severe OI were only detected with X‐ray/CT (Figure 4). The gene discussed is COL1A2; the disease is osteogenesis imperfecta.