[Otosclerosis. 1st part: pathogenesis].

Otosclerosis can be found exclusively in the human otic capsule of the temporal bone. Its etiology is still unknown. In the past decades, several potential etiopathogenetic factors have been revealed, however, most studies were based on otosclerotic patients diagnosed by clinical symptoms only. The current experience indicates that one third of this group suffer from non-otosclerotic stapes fixation. In our experimental series, we have diagnosed and classified otosclerotic patients based on histologic examination, and analyzed also the pathogenetic factors. Recent data demonstrate that measles virus and rs1800472 SNP of transforming growth factor beta 1 (TGFβ1) gene are marked obvious etiologic factors, which have no therapeutic consequences so far. Furthermore, we summarize the genetic and environmental factors to be found in the literature, which may play a fundamental role in the pathogenesis of otosclerosis. Orv Hetil. 2018; 159(30): 1215-1220.