Objective: The aim of the study was to establish the actual prevalence of these mutations in a well selected population and to redefine genotype-phenotype correlation. Methods: we have conducted a mutation analysis of the connexin 26 (Cx26) GJB2 gene in 89 individuals affected by preverbal, nonsindromic sensorineural deafness, in whom known risk factors of acquired hearing deficit had been excluded. Careful audiological assessment was performed in all subjects. Results: Mutations of the Cx26 gene were found in 49% of the individuals analyzed; of these 46% had a family history of preverbal deafness while 54% were sporadic cases. 59% of the mutated individuals were homozygote for the 35delG mutation, which accounts for 73% of all the mutated alleles. The audiological evaluation of Cx26 mutated subjects evidenced a significant inter and infra-familial variability of the level of hearing deficit, even among 35delG homozygotes. Conclusions: Our data confirm the important role played by mutations of the Cx26 gene in the etiology of nonsyndromic sensorineural deafness. The high percentage of mutations identified in cases referred to as sporadic suggests a higher than anticipated phenotype variability for this hearing defect. The strategy adopted for our molecular analysis can be efficiently used as a screening tool, with immediate advantages in diagnostics, clinical practice and genetic counseling.
|Translated title of the contribution||Clinical advantages from the molecular analysis of the Cx26 gene in preverbal sensorineural deafness|
|Number of pages||4|
|Journal||Rivista Italiana di Pediatria|
|Publication status||Published - 2000|
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health