The Prevalence of Connexin 26 Mutations in the Swedish Population

Abstract

Mutations in GJB2, the gene encoding the protein Connexin 26, have been shown to account for as much as 50% of autosomal recessive, non-syndromic childhood hearing loss (ARNSHL). Early, correct diagnosis and intervention have greatly improved the possibilities for these children in learning and developing language skills. In recent years, many reports from varied parts of the world have described the local scene of mutations in Connexin 26. The prevalence differs with geographic location and assessment procedures. Mutations in Connexin 26 have until recently been identified in very few cases in Sweden, Norway and Denmark, and nationwide population samples have not been studied in the Scandinavian countries. In this study we present the results of a large nationwide and a regional study of the prevalence of the 35delG, L90P and 167delT mutations of the GJB2 gene in Sweden. A total of 2052 samples (dried blood spots) were analysed. 1501 samples were collected representing all of Sweden and 551 samples from northern Sweden. The allele frequencies in Sweden were found to be 35delG, 0.83%; L90P, 0.30%; and 167delT, 0%. The prevalence of mutations in Connexin 26 in Sweden seems to be comparable to that in other northern European countries.

• GJB2
• 35delG
• L90P
• hearing loss
• deafness
• ARNSHL