Association of COL1A1 and otosclerosis - Evidence for a shared genetic etiology with mild osteogenesis imperfecta

Hypothesis: Otosclerosis is related to mild osteogenesis imperfecta with genetic defects in type I collagen. Background: Otosclerosis is a common bone disease of the human otic capsule that has an underlying hereditary predisposition. The histopathology and clinical manifestations are strikingly similar to the milder forms of osteogenesis imperfecta in which mutations of type I collagen genes have been established as the underlying cause. Methods: The authors investigated the genetic basis of otosclerosis by conducting an association study using polymorphic DNA markers from patients with clinical otosclerosis and random control subjects. Results: This study showed a significant association between clinical otosclerosis and the type I collagen COL1Al gene using three different polymorphic markers within the gene. Conclusions: Some cases of clinical otosclerosis may be related to mutations within the COL1Al gene that are similar to those found in mild forms of osteogenesis imperfecta and result in null expression of the mutant allele.