Hearing impairment (HI) affects 1 in 650 newborns, which makes it the most common congenital sensory impairment. Despite extraordinary genetic heterogeneity, mutations in one gene, GJB2, which encodes the connexin 26 protein and is involved in inner ear homeostasis, are found in up to 50% of patients with autosomal recessive nonsyndromic hearing loss. Because of the high frequency of GJB2 mutat...

The genetic nature of sensorineural hearing loss (SNHL) has so far been studied for many ethnic groups in various parts of the world. The single-nucleotide guanine deletion (35delG) of the GJB2 gene coding for connexin 26 was shown to be the main genetic cause of autosomal recessive deafness among Europeans. Here we present the results of the first study of GJB2 and three mitochondrial mutation...

OBJECTIVE There are many hearing impaired individuals in Monte Santo, a rural municipality in the state of Bahia, Brazil, including multiple familial cases strongly suggestive of a genetic aetiology. METHODS The present study investigated 81 subjects with hearing impairment (HI) recruited from 36 families. Mutations often associated with HI, i.e. the DFNB1 mutations c.35delG in GJB2, deletion...

OBJECTIVE Hereditary nonsyndromic deafness is an autosomal recessive condition in about 80% of cases, and point mutations in the GJB2 gene (connexin 26) and two deletions in the GJB6 gene (connexin 30), del(GJB6-D13S1830) and del(GJB6-D13S1854), are reported to account for 50% of recessive deafness. Aiming at establishing the frequencies of GJB2 mutations and GJB6 deletions in the Brazilian pop...

Mutations in the connexin 26 (Cx26) gene at the DFNB1 locus on chromosome 13q12 are associated with autosomal recessive non-syndromic hearing loss (ARNSHL). There are many known mutations in this gene that cause hearing loss. A single frameshift, at position 35 (35delG) accounts for 50% of mutations in the Caucasian population with carrier frequencies of 1.5-2.5%. In this study we investigated ...