Comprehensive molecular analysis of 61 Egyptian families with hereditary nonsyndromic hearing loss.

Nonsyndromic hearing loss is an extremely heterogeneous disorder. Thus, clinical diagnostics is challenging, in particular due to differences in the etiology of hearing loss between populations. With this study, we wanted to elucidate the genetic basis of hearing loss in 61 consanguineous Egyptian families.

Next-generation sequencing reveals the mutational landscape of clinically diagnosed Usher syndrome: copy number variations, phenocopies, a predominant target for translational read-through, and mutated in Heimler syndrome.

Background: Combined retinal degeneration and sensorineural hearing impairment is mostly due to autosomal recessive Usher syndrome (USH1: congenital deafness, early retinitis pigmentosa (RP); USH2: progressive hearing impairment, RP).

Methods: Sanger sequencing and NGS of 112 genes (Usher syndrome, nonsyndromic deafness, overlapping conditions), MLPA, and array-CGH were conducted in 138 patients clinically diagnosed with Usher syndrome.

Results: A molecular diagnosis was achieved in 97% of both USH1 and USH2 patients, with biallelic mutations in 97% (USH1) and 90% (USH2), respectively.

Computer-aided endovascular aortic repair using fully automated two- and three-dimensional fusion imaging.

Objective: To assess the usability of a fully automated fusion imaging engine prototype, matching preinterventional computed tomography with intraoperative fluoroscopic angiography during endovascular aortic repair.

Methods: From June 2014 to February 2015, all patients treated electively for abdominal and thoracoabdominal aneurysms were enrolled prospectively. Before each procedure, preoperative planning was performed with a fully automated fusion engine prototype based on computed tomography angiography, creating a mesh model of the aorta.

A TMC1 (transmembrane channel-like 1) mutation (p.S320R) in a Polish family with hearing impairment.

After excluding frequent mutations in common genes like GJB2, SLC26A4 and MT-RNR1 by straightforward Sanger sequencing in about 20 Polish families with hearing impairment, new and possibly pathogenic mutations were searched for by next-generation sequencing (NGS) screening using a specialised panel including more than 80 genes connected with hearing disorders. Due to high rates of false-positive pathogen predictions for newly discovered single-nucleotide polymorphisms (SNPs), different prediction models were combined to enhance the prediction power. In one family with a record of over four generations, II,3 and II,4 were suspected of hearing impairment without medical records.

Rare variants in BMP2 and BMP4 found in otosclerosis patients reduce Smad signaling.

Hypothesis: Genetic variation in BMP2 and BMP4 found in otosclerosis patients result in altered Smad signaling.

Background: Otosclerosis is a common form of adult-onset conductive hearing loss resulting from abnormal bone remodeling of the bony labyrinth that surrounds the inner ear. Both genetic and environmental factors are implicated in the disease, yet very little is known about its pathogenesis.

Familial aggregation of pure tone hearing thresholds in an aging European population.

Objective: To investigate the familial correlations and intraclass correlation of age-related hearing impairment (ARHI) in specific frequencies. In addition, heritability estimates were calculated.

Study Design: Multicenter survey in 8 European centers.

Ergic2, a brain specific interacting partner of Otoferlin.

Background: Otoferlin, a postulated calcium sensor of 230 kDa, was proposed to trigger calcium dependent fusion of vesicles with plasma membrane in the ribbon synapses of cochlear IHCs. Otoferlin's interaction with Rab8b and Myo6, proteins involved in the intracellular membrane trafficking, extended the previous hypothesis assigning Otoferlin an additional role in trans-Golgi trafficking. Here, we present another Otoferlin binding partner, Ergic2, a protein with a still unknown function but presenting sequence homology to other proteins involved in ER/Golgi vesicle trafficking.

The otoferlin interactome in neurosensory hair cells: significance for synaptic vesicle release and trans-Golgi network (Review).

Sound perception in terrestrial vertebrates relies on a structure in the inner ear consisting of the utriculus, sacculus and lagena. In mammals, the lagena has developed into the cochlea where mechanotransduction at ciliated cells leads to ion influx via regulated ion channels. To maintain proper Ca2+ concentration many cellular systems use a variety of functional proteins; the neurosensory systems use calcium-sensors like hippocalcin, visinin or recoverin.

Feasibility of simultaneous PET/MR imaging in the head and upper neck area.

Objective: The aim of this pilot study was to test and demonstrate the feasibility of simultaneous positron emission tomography (PET) and magnetic resonance imaging (MRI) of the head and upper neck area using a new hybrid PET/MRI system.

Methods: Eight patients with malignant head and neck tumours were included in the pilot study. Directly after routine PET/CT imaging with a whole-body system using the glucose derivative 2-[¹⁸F]fluoro-2deoxy-D-glucose (FDG) as a radiotracer additional measurements were performed with a prototype PET/MRI system for simultaneous PET and MR imaging.

Genetic variants in the RELN gene are associated with otosclerosis in multiple European populations.

Otosclerosis is a common form of hearing loss characterized by abnormal bone remodeling in the otic capsule. It is considered a complex disease caused by both genetic and environmental factors. In a previous study, we identified a region on chr7q22.

Otoferlin interacts with myosin VI: implications for maintenance of the basolateral synaptic structure of the inner hair cell.

Otoferlin has been proposed to be the Ca(2+) sensor in hair cell exocytosis, compensating for the classical synaptic fusion proteins synaptotagmin-1 and synaptotagmin-2. In the present study, yeast two-hybrid assays reveal myosin VI as a novel otoferlin binding partner. Co-immunoprecipitation assay and co-expression suggest an interaction of both proteins within the basolateral part of inner hair cells (IHCs).

Deafness in TRbeta mutants is caused by malformation of the tectorial membrane.

Thyroid hormone receptor beta (TRbeta) dysfunction leads to deafness in humans and mice. Deafness in TRbeta(-/-) mutant mice has been attributed to TRbeta-mediated control of voltage- and Ca(2+)-activated K(+) (BK) channel expression in inner hair cells (IHCs). However, normal hearing in young constitutive BKalpha(-/-) mutants contradicts this hypothesis.

GRM7 variants confer susceptibility to age-related hearing impairment.

Age-related hearing impairment (ARHI), or presbycusis, is the most prevalent sensory impairment in the elderly. ARHI is a complex disease caused by an interaction between environmental and genetic factors. Here we describe the results of the first whole genome association study for ARHI.

Impact of genotype and mutation type on health-related quality of life in patients with hereditary hemorrhagic telangiectasia.

Conclusions: Patients with hereditary hemorrhagic telangiectasia genotype ALK-1 (HHT2-ALK-1) with nonsense mutation demonstrated tendentially higher health-related quality of life (HR-QOL) scores than patients with HHT with genotype ENG (HHT1-ENG) with missense mutation.

Objective: HHT, also known as Osler-Weber-Rendu syndrome, comprises different expressions depending on genetic type and mutation type. The influence of HHT type on HR-QOL has not been established and is addressed in this paper.

Rab8b GTPase, a protein transport regulator, is an interacting partner of otoferlin, defective in a human autosomal recessive deafness form.

Mutations within OTOF encoding otoferlin lead to a recessive disorder called DFNB9. Several studies have indicated otoferlin's association with ribbon synapses of cochlear sensory hair cells, as well as data showing the protein's presence in neurons, nerve fibers and hair cells, suggesting a more ubiquitous function. Otoferlin's co-localization not only with ribbon synaptic proteins, but also with additional endosomal (EEA1) or Golgi proteins (GM130) were motivation for a search for further binding partners of otoferlin by a yeast two-hybrid screen in a rodent cochlear cDNA library (P3-P15).

Genome-wide SNP-based linkage scan identifies a locus on 8q24 for an age-related hearing impairment trait.

Age-related hearing impairment (ARHI), or presbycusis, is a very common multifactorial disorder. Despite the knowledge that genetics play an important role in the etiology of human ARHI as revealed by heritability studies, to date, its precise genetic determinants remain elusive. Here we report the results of a cross-sectional family-based genetic study employing audiometric data.

Occupational noise, smoking, and a high body mass index are risk factors for age-related hearing impairment and moderate alcohol consumption is protective: a European population-based multicenter study.

A multicenter study was set up to elucidate the environmental and medical risk factors contributing to age-related hearing impairment (ARHI). Nine subsamples, collected by nine audiological centers across Europe, added up to a total of 4,083 subjects between 53 and 67 years. Audiometric data (pure-tone average [PTA]) were collected and the participants filled out a questionnaire on environmental risk factors and medical history.

Lack of Tff3 peptide results in hearing impairment and accelerated presbyacusis.

Tff peptides are secreted mainly by the gastrointestinal epithelial cells and their primary role is maintaining normal structure and function of mucous epithelia. Ongoing studies on their expression pattern have disclosed other sites of their synthesis thus revealing additional physiological functions in the organism. Here we present new data about Tff3 expression in the cochlea of the rodent inner ear.

The contribution of GJB2 (Connexin 26) 35delG to age-related hearing impairment and noise-induced hearing loss.

Hypothesis: The common GJB2 (Connexin 26) 35delG mutation might contribute to the development of age-related hearing impairment (ARHI) and noise-induced hearing loss (NIHL).

Background: GJB2, a gene encoding a gap junction protein expressed in the inner ear, has been suggested to be involved in the potassium recycling pathway in the cochlea. GJB2 mutations account for a large number of individuals with nonsyndromic recessive hearing loss, with 35delG being the most frequent mutation in populations of European origin.

Coincidence of mutations in different connexin genes in Hungarian patients.

Mutations in the GJB2 gene are the most common cause of hereditary prelingual sensorineural hearing impairment in Europe. Several studies indicate that different members of the connexin protein family interact to form gap junctions in the inner ear. Mutations in different connexin genes may accumulate and, consequently lead to hearing impairment.