title: Temporal bone abnormalities in children with GJB2 mutations.
abstract: OBJECTIVE
  To determine the incidence of temporal bone abnormalities in children with sensorineural hearing loss (SNHL) and pathogenic biallelic GJB2 mutations.
  
  
  METHODS
  Retrospective analysis of a large cohort of pediatric patients with biallelic GJB2 mutations and SNHL (observational case series).
  
  
  METHODS
  Blinded review of all available temporal bone computed tomographic (CT) and magnetic resonance imaging (MRI) studies in this cohort.
  
  
  RESULTS
  Out of 158 patients with biallelic GJB2 mutations, 113 had CT and/or MRI studies available for review. Definite, although generally subtle, inner ear abnormalities were present in 12/113. There were malformations of the semicircular canals (SCC) in 4/12, of the internal auditory canal in 2/12, of the cochlear nerve canal (CNC) in 6, and unilateral cochlear malformation in 1/12. MRI in 1/5 showed mildly hypoplastic cochlear nerve. There was no correlation between SNHL severity and presence/absence/type of malformations or genotype.
  
  
  CONCLUSIONS
  Our study of 113 biallelic GJB2 patients with SNHL and temporal bone imaging is the largest study to date. We found only 10% had any abnormalities, most subtle, and none had EVA. Additionally, there was no correlation between SNHL severity and presence/absence/type of malformations or genotype. Disparities between our group and previous reports may be due to differences in degree of hearing loss, types of mutations, populations studied, and radiologic factors for both image acquisition and interpretation.
authors.affiliation: Department of Otolaryngology and Communication Enhancement, Children's Hospital Boston, Boston, Massachusetts, USA. margaret.kenna@childrens.harvard.edu
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Kenna
authors.forename: Heidi L
authors.initials: HL
authors.lastname: Rehm
authors.forename: Anna
authors.initials: A
authors.lastname: Frangulov
authors.forename: Henry A
authors.initials: HA
authors.lastname: Feldman
authors.forename: Caroline D
authors.initials: CD
authors.lastname: Robson
mesh_terms: D000293:Adolescent; D000483:Alleles; D002648:Child; D002675:Child, Preschool; D003051:Cochlea / Q000002:abnormalities; D003056:Cochlear Nerve / Q000002:abnormalities; D015331:Cohort Studies; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D004252:DNA Mutational Analysis; D003638:Deafness / Q000175:diagnosis / Q000235:genetics*; D005260:Female; D005838:Genotype; D046089:Hearing Loss, Mixed Conductive-Sensorineural / Q000175:diagnosis / Q000235:genetics*; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000235:genetics*; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D010579:Petrous Bone / Q000002:abnormalities; D012665:Semicircular Canals / Q000002:abnormalities; D013223:Statistics as Topic; D013701:Temporal Bone / Q000002:abnormalities*; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D017630:Connexins; C000607042:GJB2 protein, human; D000072259:Connexin 26