introduction: hearing loss is the most common sensory neural defect in humans, affecting 1 in 1000 neonates, with over half of these cases predicted to be hereditary in nature. most hereditary hearing loss is inherited in a recessive fashion, accounting for approximately 80 % of non-syndromic hearing loss (nshl). mutations in gjb2 gene are major cause of inherited deafness in the european and a...

background: autosomal recessive non-syndromic hearing loss (arnshl) is the most common hereditary form of deafness, and exhibits a great deal of genetic heterogeneity. so far, more than seventy various dfnb loci have been mapped for arnshl by linkage analysis. the contribution of three common dfnb loci including dfnb3, dfnb9, dfnb21 and gap junction beta-2 (gjb2) gene mutations in arnshl was in...

Objective: The aim of this study is to establish a method by single nucleotide polymorphism detection from a single cell using the whole genomic amplification and restriction fragment length polymorphism-PCR (RFLPPCR). Methods: Genomic DNA was first prepared and wholly amplified from 80 biopsied blastomeres using the Sure Plex DNA Amplification System. Then, PCR was carried out on a single blas...

The understanding of the molecular genetics in sensorineural hearing loss (SNHL) has advanced rapidly during the last decade, but the molecular etiology of hearing impairment in the Portuguese population has not been investigated thoroughly. To provide appropriate genetic testing and counseling to families, we analyzed the whole mitochondrial genome in 95 unrelated children with SNHL (53 nonsyn...

Background: Congenital hearing loss due to different genetic and environmental causes affects 1 in 1000 newborns. Mutations in the GJB2 (Gap Junction Beta-2) gene encoding the gap junction protein connexin 26 have been established as the main cause of autosomal recessive non-syndromic hearing loss. Materials and methods: The aim of this study was to study the frequency of GJB2 Mutations in Lor...

The incidence of pre-lingual hearing loss (HL) is about 1 in 1000 neonates. More than 60% of cases are inherited. Non-syndromic HL (NSHL) is extremely heterogeneous: more than 130 loci have been identified so far. The most common form of NSHL is the autosomal recessive form (ARNSHL). In this study, a cohort of 36 big ARNSHL pedigrees with 4 or more patients from 7 provinces of Iran was investig...

Keratitis-ichthyosis-deafness syndrome is a rare genodermatosis, which has recently been connected with mutations in the connexin-26 gene, GJB2. We present a 15-year-old boy with erythroderma, hyperkeratotic plaques and deafness. Sequencing analysis showed a heterozygous missense mutation D50N (148G>A) in GJB2. The boy has not yet manifested characteristic eye lesions but his case shows that ta...