Lastly, using multidimensional scaling and ADMIXTURE analyses, we delineate the degree of Asian/European admixture in the HI families understudy, and show that Roma individuals carrying the GJB2p.(Trp24*) and MANBA c.2158-2A>G variants have a more pronounced South Asian background, whereas the other hearing-impaired Roma display an ancestral background similar to Europeans.
Our study aimed to investigate GJB2 (connexin 26) and GJB6 (connexin 30) mutations associated with non-syndromic childhood hearing impairment (HI) as well as the environmental causes of HI in Ghana.
Verified GJB2-negative samples were subsequently subjected to whole exome sequencing (WES) to identify the underlying causes of hearing impairment, and the variants identified in each family were further confirmed by Sanger sequencing.
This study aimed to investigate <i>GJB2</i> (connexin 26) and <i>GJB6</i> (connexin 30) mutations associated with familial non-syndromic childhood hearing impairment (HI) in Cameroon.
Hearing impairment (HI) caused by mutations in the connexin-26 gene (GJB2) accounts for the majority of cases with inherited, nonsyndromic sensorineural hearing loss.
This is perhaps the first study in the world to test real-time, the hypothesis proposed by Nance et al. in 2000 (intense phenotypic assortative mating mechanism can double the frequency of the commonest forms of recessive deafness [DFNB1]) in assortative mating HI parental generation and their offspring.
In our cohort the hearing impairment and age of onset was not altered between in cases with only one heterozygous GJB2 mutation and wild type genotype, which may exclude the possibility of autosomal dominant inheritance.
Importantly, we also demonstrate that the antibody efficiently inhibits hyperative mutant Cx26 hemichannels implicated in autosomal dominant non-syndromic hearing impairment accompanied by keratitis and hystrix-like ichthyosis-deafness (KID/HID) syndrome.
We report here a non consanguineous assortatively mating hearing impaired family with one of the hearing impaired partners, their hearing impaired sibling and hearing impaired offspring showing compound heterozygosity in the GJB2 gene, involving a dominant mutation p.R184Q and two recessive mutations p.Q124X and c.IVS 1+1G>A in a unique triallelic combination.
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.
We finally discuss the diversity of clinical features of DFNB1HI as regards severity, age of onset, inner ear malformations and vestibular dysfunction, highlighting the areas where future research should be concentrated.
We delineated the longitudinal auditory features of the highly prevalent GJB2p.V37I mutation on a general population basis and confirmed the utility of newborn genetic screening in identifying infants with late-onset or progressive hearing impairment undetectable by newborn hearing screening.Genet Med 19 1, 6-12.
Alterations within a novel putative Exon 1a within the gap junction beta 2 (GJB2) gene may play a role in the development of genetic hearing impairment in Austria.
Regarding the genetic cause, specific founder mutations in GJB2 gene (R143W, L79P, V178A, R184Q, A197S, I203K, and L214P) was the only identified genetic cause of HI in Ghana, but the other HI genes were not investigated.
The complete sequencing of the non-coding and coding regions of the GJB2 gene was performed in 393 patients with HI (Yakuts-296, Russians-51, mixed and other ethnicities-46) and in 187 normal hearing individuals of Yakut (n = 107) and Russian (n = 80) populations.
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.
The c.-259C>T mutation, previously described as -3438C>T, is not a common cause of non-syndromic hearing impairment alone or together with heterozygous pathogenic GJB2 mutations that are statistically overrepresented in non-syndromic hearing impaired patient groups.