ABSTRACT
Osteogenesis imperfecta (OI) (1) is a group of heterogeneous disorders with the common feature of congenital bone fragility, caused by mutations in the genes that codify for type I procollagen (COL1A1 and COL1A2)(Table 1). These two genes are located in chromosomes 7 and 17. A comprehensive listing of the mutations within type I collagen genes resulting in OI (2) is maintained in the internet (3). In the vast majority of cases, OI is inherited in a dominant fashion or is caused by a newmutation, but a case of a family in which OI was recessive has been published (4). The prevalence of OI is estimated to be 1 in 20,000 to 50,000 infants (5), but the incidence is probably higher, because being a heterogeneous conditionmisdiagnosis is frequent. The prevalence of OI appears to be similar throughout the world and in all races (6-9).
