Tooth agenesis in osteogenesis imperfecta related to mutations in the collagen type I genes

Background Osteogenesis imperfecta (OI) is a heterogeneous group of disorders of connective tissue, mainly caused by mutations in the collagen type I genes (COL1A1 and COL1A2). Tooth agenesis is a common feature of OI. We investigated the association between tooth agenesis and collagen type I mutations in individuals with OI. Subjects and methods In this cohort study, 128 unrelated individuals with OI were included. Panoramic radiographs were analyzed regarding dentinogenesis imperfecta (DGI) and congenitally missing teeth. The collagen I genes were sequenced in all individuals, and in 25, multiplex ligation‐dependent probe amplification was performed. Results Mutations in the COL1A1 and COL1A2 genes were found in 104 of 128 individuals. Tooth agenesis was diagnosed in 17% (hypodontia 11%, oligodontia 6%) and was more frequent in those with DGI (P = 0.016), and in those with OI type III, 47%, compared to those with OI types I, 12% (P = 0.003), and IV, 13% (P = 0.017). Seventy‐five percent of the individuals with oligodontia (≥6 missing teeth) had qualitative mutations, but there was no association with OI type, gender, or presence of DGI. Conclusion The prevalence of tooth agenesis is high (17%) in individuals with OI, and OI caused by a qualitative collagen I mutation is associated with oligodontia.