Here we provide detailed description of two related individuals with the skeletal phenotype of OP-CDL but without a pathogenic variant in SGMS2. Instead, both harbor a novel heterozygous missense mutation p.N48S in IFITM5, a genetic defect previously primarily reported in OI type V and, in a few cases, OI type VI [1, 11–18]. This evidence concerns the gene IFITM5 and osteogenesis imperfecta type 5.