Questão 1118827

Osteogenesis imperfecta (OI) is defined as a disease characterized by bone fragility caused by a qualitative or quantitative defect in type 1 collagen, synthesized by osteoblasts. The estimated number of OI cases in the United States of America is 1 per every 20,000 to 25,000 live births. In Brazil, however, this information is not known. OI corresponds to a group of hereditary disorders, mostly autosomal dominant, caused by numerous mutations in one of the two genes that encode the alpha chains - COL1A1 and COL1A2 of type 1 collagen. In about 80% to 90% of its carriers, mutations in one of these genes can be identified. The presence of abnormal structural proteins determines bone fragility. The severity of the findings varies greatly, from lethal forms of intrauterine fractures to fractures that only occur in adolescence and adulthood. Some patients have compromised height, as well as dentinogenesis imperfecta, blue sclerae, and ligamentous laxity, as type 1 collagen is also present in teeth, skin, tendons, and sclera.

Internet: <www.portalarquivos2.saude.gov.br> (adapted).

According to the previous text, in this pathology,