Through whole exome sequencing, two groups recently identified a single point mutation (c.-14C > T) in the 5’ untranslated region (UTR) of the gene encoding interferon-induced transmembrane protein 5 (IFITM5, also known as Bril) as the cause of OI type V (GenBank ID rs373183215) [9,10]. The gene discussed is IFITM5; the disease is osteogenesis imperfecta type 5.