COL1A1 and osteogenesis imperfecta: These included genes linked to Fraser syndromes (Fras1, Frem2, Grip1), osteogenesis imperfecta and related bone fragility (Bmp1a, Col1a1, Col1a2, Col2a1), skeletal dysplasia (Fgfr3, Flnb, Nek1, Ebp), limb and heart malformations (Tbx5a), and cutaneous or connective tissue disorders (St14, Lmna, Pex1, Aspa).