Bone Abstracts

Objectives: Osteogenesis Imperfecta (OI), is a group of rare, heritable disorder of bone and connective tissue. The pathogenicity of OI arises from the mutations in about 17 different genes, involved in collagen type 1 synthesis, processing, post-translational modification, folding, cross-linking, bone mineralization, and osteoblast differentiation. Based on Sillence classification, there are four types of OI; Type I (mild, non-deforming), Type II (perinatal lethal), Type III (severely deforming), and Type IV (moderately deforming). The aim of this study was to collect the preliminary epidemiological and clinical information of Iranian patients with OI

Methods: Sixty-seven of Iranian patients, 42 (62.7%) males and 25 (37%) females) average age: 9.6(, clinically diagnosed as OI patients and classified according to Sillence classification, enrolled into the study for observational investigations and data collection. A questionnaire was designed and the demographic and clinical features of the patients were recorded.

Results: Of 67 OI patients, types IV, III, I, and not identified cases (unknown) were found to be 24%, 30%, 15%, and 31%, respectively. To diagnose the OI type in the latter, more investigations and tests are needed to be done. In most of the patients, the first fractures had occurred between 1 month and 2-year ages (26/67). The rate of consanguineous marriages was found to be almost 64% among which 70% did not have any positive history of OI. Blue/gray sclera was seen in 66% of the patients. 41 cases showed thoracic cage deformity (from mild to severe), and 22 cases had scoliosis/kyphoscoliosis. Forty-seven patients had lower limb deformity, although, the upper limb deformity was seen in 35 patients.

Conclusion: In our preliminary data collection, type III of OI was found to be the most frequent one compared with the other types of OI. Although some of the unidentified cases might change the presented figures after being more analyzed. A higher number of the patients in our study were from consanguineous marriages, whose family did not have any history of OI. This might have an indication of either recessive or novel de novo mutations, the definite diagnosis of which requires molecular analysis.

Disclosure: The authors declared no competing interests.