Aim: 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.
Conclusion: Congenital CMV infection is a high risk factor in hearing impairment among children.