OSTEOGENESIS IMPERFECTA TYPE IV OMIM

Description: Alternative titles OI, TYPE IV OSTEOGENESIS IMPERFECTA WITH NORMAL SCLERAE Gene map locus 17q21.31-q22 TEXT A number sign (#) is used with this entry because osteogenesis imperfecta type IV can be caused by mutation in the COL1A1 gene (120150) or the COL1A2 gene (120160). DESCRIPTION Osteogenesis imperfecta (OI) is a connective tissue disorder that is caused by an abnormality of type I collagen in over 90% of cases. Due to considerable phenotypic variability, Sillence et al. (1979) developed a classification of OI subtypes: OI type I with blue sclerae (166200); perinatal lethal OI type II, also known as congenital OI (166210); OI type III, a progressively deforming form with normal sclera (259420); and OI type IV, with normal sclerae. Levin et al. (1978) suggested that OI subtypes could be further divided into types A and B based on the absence or presence of dentinogenesis imperfecta.