Clinical studies of families with hearing loss attributable to mutations in the connexin 26 gene (GJB2/DFNB1)

摘要: Objective. This retrospective study describes the phenotype associated with single most common cause of genetic hearing loss. The frequency childhood deafness is estimated at 1/500. Half this loss and ∼80% nonsyndromic inherited in an autosomal recessive manner. Approximately 50% caused by mutations connexin 26 (Cx26) gene (GJB2/DFNB1), making it form a carrier rate to be as high 2.8%. One mutation, 35delG, accounts for ∼75% 80% gene. Methods. Hearing was examined 46 individuals from 24 families who were either homozygous or compound heterozygous Cx26 mutations. A subset these vestibular function, otoacoustic emissions, auditory brainstem response, temporal bone computed tomography, electrocardiography, urinalyses, dysmorphology, thyroid function. Results. Although all persons had impairment, no consistent audiologic observed. varied mild-moderate profound, even within group mutation suggesting that other factors modify phenotypic effects Cx26. Furthermore, observed progressive number cases. No associations inner ear abnormality, dysfunction, heart conduction defect, dysmorphic features, retinal abnormality noted. Conclusion. Newborns confirmed should have testing. testing will help define which ∼60% profound severe-profound require aggressive language intervention (many patients candidates cochlear implants). Pediatrics 1999;103:546-550; 26, GJB2, DFNB1, loss,