title: Congenital cytomegalovirus infection - a common cause of hearing loss of unknown aetiology.
abstract: OBJECTIVE
  The aim of this study was to investigate the role of congenital cytomegalovirus (CMV) infection as a cause of various types of sensorineural hearing loss (SNHL) in a group of nonsyndromic children with otherwise unknown aetiology of hearing loss. Furthermore, the occurrence of combined congenital CMV infection and connexin 26 (Cx26) mutations was investigated.
  
  
  METHODS
  The dried blood spot (DBS) cards of 45 children with various degrees of hearing deficits and 46 children with severe/profound hearing loss were tested for CMV DNA with polymerase chain reaction (PCR) technique. The DBS cards of the 46 children with severe/profound hearing loss were also analysed for Cx26 mutations.
  
  
  RESULTS
  Of the 45 children with various degrees of hearing loss, nine were positive for CMV DNA (20%). The nine children represented severe/profound, mild and unilateral hearing loss. From the 46 children with severe/profound hearing loss, nine of 46 (20%) were positive for CMV DNA. In addition, three of the CMV DNA-positive children were carriers of mutations of Cx26.
  
  
  CONCLUSIONS
  Congenital CMV infection is a high risk factor in hearing impairment among children.
authors.affiliation: Department of Otorhinolaryngology, Karolinska University Hospital, Stockholm, Sweden. eva.karltorp@karolinska.se
authors.forename: Eva
authors.initials: E
authors.lastname: Karltorp
authors.forename: Sten
authors.initials: S
authors.lastname: Hellström
authors.forename: Ilona
authors.initials: I
authors.lastname: Lewensohn-Fuchs
authors.forename: Eva
authors.initials: E
authors.lastname: Carlsson-Hansén
authors.forename: Per-Inge
authors.initials: PI
authors.lastname: Carlsson
authors.forename: Mona-Lisa
authors.initials: ML
authors.lastname: Engman
mesh_terms: D000293:Adolescent; D002648:Child; D015331:Cohort Studies; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D003587:Cytomegalovirus / Q000235:genetics / Q000302:isolation & purification; D003586:Cytomegalovirus Infections / Q000150:complications* / Q000151:congenital / Q000175:diagnosis; D004279:DNA, Viral / Q000032:analysis; D059788:Dried Blood Spot Testing; D005819:Genetic Markers; D006312:Hearing Loss, Bilateral / Q000235:genetics / Q000821:virology; D006319:Hearing Loss, Sensorineural / Q000235:genetics / Q000821:virology*; D046088:Hearing Loss, Unilateral / Q000235:genetics / Q000821:virology; D006801:Humans; D009154:Mutation; D016133:Polymerase Chain Reaction; D012042:Registries; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index
chemical_list: D017630:Connexins; D004279:DNA, Viral; C000607042:GJB2 protein, human; D005819:Genetic Markers; D000072259:Connexin 26