Background: Osteogenesis imperfecta is an inherited disorder particularily of a human connective tissue. It is a worldwide extensive disorder regardless of age, gender or ethnic group. At present the disease includes nine clinically different types. Typical clinical features are brittle bones, high frequency of fractures and bone deformities. The other observed signs are blue sclera, dentinogenesis imperfect and otosclerosis. The first four types of the disease arise from mutations in collagen type I genes, composed from COL1A1 and COL1A2 chains. A result of these mutations is the production of shortened or structurally defective protein. Individuals affected by OI forms V to IX have mutations in proteins encoded by following genes: CRTAP, LEPRE1, PPIB, FKBP10. Collagenous types of the illness exhibit a broad range of severity depending on type and mutation localization in the structure of the collagen type I. Objectives and Methods: The aim of this study is the description of the clinical forms of the disease, identifying mutations and polymorphisms of genes of the collagen type I by a molecular genetic analysis of genomic DNA of Czech OI patients. Results: Currently in the Czech population there are described mutations and polymorphisms only of MLBR2 region, namely exons 31, 33 and 36 and introns 32 and 39, of the COL1A1 gene of 25 OI patients. Mgr. Lucie ŠormováConclusion: It is important to perform a further molecular genetic analysis of both collagen type I genes for the detection of the widest possible mutational spectrum for determination of possible genotype phenotype relationship of affected individuals.

Background: Osteogenesis imperfecta is a worldwide widespread disorder of connective tissue characterized by extensive clinical heterogeneity. The main clinical feature is increased bone fragility due to defective collagen type I production which is encoded by two genes-COL1A1 and COL1A2. Based on clinical, radiological and genetic features there is described 11 forms of the disease. Only the first four types result from the collagen type I mutations. Severity of the disorder ranges from mild to lethal forms. Objectives and Methods: The aim of this study is the molecular-genetic analysis of COL1A1 gene of 25 Czech patients suffering from the disease named osteogenesis imperfecta, specifically type I-IV, and comparison of clinical pictures of individuals with the same identified mutations. Results: COL1A1 gene mutations were identified in three of twenty-five Czech OI patients. These individuals come from unrelated families and are affected by osteogenesis imperfecta type IA, III and IVB. Conclusion: Further molecular-genetic analyses of other patients and their relatives are important for detection of the biggest mutational spectrum necessary for determination of possible genotype phenotype relationship of affected individuals and for comparison the Czech population with others countries.