Finally a genetic classification of Osteogenesis Imperfecta has been delineated thanks to efforts of JC Marini and A Forlino. The advances in gene studies and molecular biology led to understanding how a recessive point mutation in a subunits of a tripeptide protein like collagen should have a dominant negative effect. Two kinds of Osteogenesis Imperfecta should be diagnosed: those associated with an autosomal dominant mutation ( AD ) involving the genes coding for procollagen alfa 1 and alfa 2 genes and those involving the genes coding for enzimes involved into procollagen maturation ( AR ).
Now 12 types of Osteogenesis Imperfecta have been described.
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