title: Clinical and genetic analysis of two Tunisian otosclerosis families.
abstract: Otosclerosis is caused by an abnormal bone homeostasis of the otic capsule resulting in a conductive hearing loss when the free motion of the stapes is compromised. An additional sensorineural hearing loss arises in some patients, most likely due to otosclerotic foci that invade the cochlear endosteum. Otosclerosis is a very common hearing impairment among Caucasians with a prevalence of about 0.3-0.4% among white adults. In the majority of cases, otosclerosis can be considered as a complex disease, caused by both genetic as environmental factors, but autosomal dominant forms of otosclerosis exist. However, families large enough for genetic analysis are very rare and often show reduced penetrance. To date five loci have been reported, but none of the genes have been cloned yet. In this study, we analyzed two new autosomal dominant otosclerosis families from Tunisia, and genotyped them with microsatellite markers for the known loci, the collagen genes COL1A1 and COL1A2, and NOG gene. In the family LK, linkage to all known loci was excluded. However, the family LS shows suggestive linkage to the OTSC3 region on chromosome 6p21.3-p22.3. This result points out that, besides the five reported loci, there must be at least one additional locus for autosomal dominant otosclerosis.
authors.affiliation: Unité d'Epidémiologie Génétique et Moléculaire-Faculté de Médecine de Tunis, Tunisia.
authors.forename: Insaf Bel Hadj
authors.initials: IB
authors.lastname: Ali
authors.forename: Melissa
authors.initials: M
authors.lastname: Thys
authors.forename: Najeh
authors.initials: N
authors.lastname: Beltaief
authors.forename: Isabelle
authors.initials: I
authors.lastname: Schrauwen
authors.forename: Nele
authors.initials: N
authors.lastname: Dieltjens
authors.forename: Kathleen
authors.initials: K
authors.lastname: Vanderstraeten
authors.forename: Ghazi
authors.initials: G
authors.lastname: Besbes
authors.forename: Emna
authors.initials: E
authors.lastname: Mnif
authors.forename: Slah
authors.initials: S
authors.lastname: Hachicha
authors.forename: Saïda Ben
authors.initials: SB
authors.lastname: Arab
authors.forename: Guy Van
authors.initials: GV
authors.lastname: Camp
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002352:Carrier Proteins / Q000235:genetics; D002874:Chromosome Mapping; D002896:Chromosomes, Human, Pair 6 / Q000235:genetics; D003094:Collagen / Q000235:genetics; D024042:Collagen Type I / Q000235:genetics; D000090602:Collagen Type I, alpha 1 Chain; D004252:DNA Mutational Analysis; D005192:Family Health; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005838:Genotype; D006801:Humans; D008126:Lod Score; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D010040:Otosclerosis / Q000235:genetics* / Q000473:pathology*; D010375:Pedigree; D014416:Tunisia; D000099176:Noggin Protein
chemical_list: D002352:Carrier Proteins; D003094:Collagen; D024042:Collagen Type I; D000090602:Collagen Type I, alpha 1 Chain; D000099176:Noggin Protein