Among about 90 genes, which are known to be associated with hearing impairment, mutations in the GJB2 (gap junction protein beta 2) gene are the most prevalent in individuals with hereditary hearing loss.
An important gene that should be considered in congenital or childhood onset autosomal recessive HI is GJB2 since mutations in this gene account for at least 50% of this type of HI.
Analyses of gap junction protein beta-2 and -6 genes revealed that similar pathological genotypes, occurring with similar frequencies, were responsible for progressive hearing loss, compared with reported genotypes for non-progressive hearing loss patients.
As GJB2 follows a recessive pattern of inheritance, the question arises as to why such a large fraction of simple heterozygotes was observed among the hearing impaired patients included in this study.
As the first comprehensive study in Iran, we have targeted GJB2-related Iranian heterozygotes, looking for second mutant allele which leads to hearing impairment.
Audiograms of 62 patients (56 families) with biallelic GJB2 mutations typically indicated a profound hearing loss with T/T mutations, moderate hearing loss with T/NT mutations, and mild hearing impairment with NT/NT mutations (p < 0.01, Student's t test).
Autosomal recessive non-syndromic hearing loss in the Lebanese population: prevalence of the 30delG mutation and report of two novel mutations in the connexin 26 (GJB2) gene.
Because of its high frequency, DFNB1hearing impairment has received continued attention from researchers along the years, resulting in a wealth of data that is unparalleled among these disorders.
Because of the high frequency of DFNB1 gene mutations and the availability of genetic diagnostic tests involving these genes, they are the best candidates to develop a risk prediction model of being hearing impaired.
Common mutation analysis of GJB2 and GJB6 genes in affected families with autosomal recessive non-syndromic hearing loss from Iran: simultaneous detection of two common mutations (35delG/del(GJB6-D13S1830)) in the DFNB1-related deafness.
Despite the many studies on the involvement of GJB2 mutations in hearing impairment in different populations, there is little information on genetic deafness in Brazil, especially in the Amazon region.
Direct sequence of GJB2 was conducted over seven cochlear implant users with prelingual hearing impairment and their speech, language and cognitive performance was examined.
Dominant mutations of GJB2-encoding connexin-26 (Cx26) have pleiotropic effects, causing either hearing impairment (HI) alone or in association with palmoplantar keratoderma (PPK/HI).
Finally, our study suggests that GJB2 should be screened for heterozygous mutations in patients with autosomal dominant isolated hearing impairment, whatever the severity of the disease.