title: Bilateral semicircular canal aplasia.
abstract: BACKGROUND
  Bilateral semicircular canal aplasia is extremely rare; discovery, when the cochlear-vestibular system is normal and there is no hearing loss, is serendipitous.
  
  
  METHODS
  Bilateral semicircular canal aplasia was serendipitously discovered in a 24-year-old male during assessment of unilateral mixed hearing loss with subnormal contralateral hearing. The deformity was isolated, with no associated syndrome.
  
  
  CONCLUSIONS
  Incidence of this isolated entity is unknown, but doubtless greatly underestimated due to the absence of associated symptomatology. To the best of our knowledge, this is only the second report of bilateral aplasia of the entire semicircular canal system involving unilateral hearing loss. A review of the literature focuses on the embryological and molecular aspects.
authors.affiliation: Service d'Oto-Rhino-Laryngologie et Chirurgie Cervico-Faciale, CHU d'Angers, 4, rue Larrey, 49100 Angers, France. Electronic address: renaud.breheret@gmail.com.
authors.forename: R
authors.initials: R
authors.lastname: Breheret
authors.affiliation: Service d'Oto-Rhino-Laryngologie et Chirurgie Cervico-Faciale, CHU d'Angers, 4, rue Larrey, 49100 Angers, France.
authors.forename: C
authors.initials: C
authors.lastname: Brecheteau
authors.affiliation: Service de Radiologie, CHU d'Angers, 4, rue Larrey, 49100 Angers, France.
authors.forename: J-Y
authors.initials: JY
authors.lastname: Tanguy
authors.affiliation: Service d'Oto-Rhino-Laryngologie et Chirurgie Cervico-Faciale, CHU d'Angers, 4, rue Larrey, 49100 Angers, France.
authors.forename: L
authors.initials: L
authors.lastname: Laccourreye
mesh_terms: D003056:Cochlear Nerve / Q000002:abnormalities; D005072:Evoked Potentials, Auditory; D046089:Hearing Loss, Mixed Conductive-Sensorineural / Q000209:etiology; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008297:Male; D035583:Rare Diseases; D012665:Semicircular Canals / Q000002:abnormalities*; D055815:Young Adult
keywords: CHARGE syndrome; Congenital inner ear malformation; Semicircular canal aplasia