Type : Phenotype or locus, molecular basis unknown;
Alternative titles and symbols : OTS;
Description : Clinical otosclerosis, the single most common cause of hearing impairment, is characterized
by isolated endochondral bone sclerosis of the labyrinthine capsule. Otosclerotic
foci invade the stapediovestibular joint (oval window) and interfere with free motion
of the stapes. Mean age of onset is in the third decade and 90% of affected persons
are under 50 years of age at the time of diagnosis. Approximately 10% of affected
persons develop profound sensorineural hearing loss across all frequencies (summary
by Tomek et al., 1998). - Genetic Heterogeneity of Otosclerosis The locus associated
with otosclerosis-1 (OTSC1) has been mapped to chromosome 15q26.1. Other loci associated
with otosclerosis include;
Inheritance : Autosomal dominant with reduced penetrance;