Genetic errors (mutations) in the gene KDELR2 in patients cause the brittle bone disease Osteogenesis Imperfecta. The bones of these patients are fragile and can break easily so patients can experience many fractures during their lifetime. Bones can also be misshapen. Osteogenesis Imperfecta affects in general 1 in 15-20,000 people but it is not yet known how many people are specifically affected as a result of KDELR2 mutations. The disease can occur in children of parents who are carriers of a mutation in the KDELR2 gene.