There were also three patients with differentially classified variants in COL1A1. Pathogenic variants in COL1A1 are causal for Ehlers–Danlos syndrome (type I and VII), osteogenesis imperfecta (type I-IV), osteoporosis, and Caffey diseases (https://www.omim.org/entry/120150). This evidence concerns the gene COL1A1 and osteoporosis.