Hereditary hearing loss is a monogenic disease with high genetic heterogeneity. Variants in more than 100 deafness genes underlie the basis of its pathogenesis. The aim of this study was to assess the ratio of SNVs in known deafness genes contributing to the etiology of both sporadic and familial sensorineural hearing loss patients from China. DNA samples from 1127 individuals, including normal hearing controls (n = 616), sporadic SNHL patients (n = 433), and deaf individuals (n = 78) from 30 hearing loss pedigrees were collected. The NGS tests included analysis of sequence alterations in 129 genes. The variants were interpreted according to the ACMG/AMP guidelines for genetic hearing loss combined with NGS data from 616 ethnically matched normal hearing adult controls. We identified a positive molecular diagnosis in 226 patients with sporadic SNHL (52.19%) and in patients from 17 deafness pedigrees (56.67%). Ethnically matched MAF filtering reduced the variants of unknown significance by 8.7%, from 6216 to 5675. Some complexities that may restrict causative variant identification are discussed. This report highlight the clinical utility of NGS panels identifying disease-causing variants for the diagnosis of hearing loss and underlines the importance of a broad data of control and ACMG/AMP standards for accurate clinical delineation of VUS variants.

The middle ear conducts sound to the cochlea for hearing. Otitis media (OM) is the most common illness in childhood. Moreover, chronic OM with effusion (COME) is the leading cause of conductive hearing loss. Clinically, COME is highly associated with Primary Ciliary Dyskinesia, implicating significant contributions of cilia dysfunction to COME. The understanding of middle ear cilia properties that are critical to OM susceptibility, however, is limited. Here, we confirmed the presence of a ciliated region near the Eustachian tube orifice at the ventral region of the middle ear cavity, consisting mostly of a lumen layer of multi-ciliated and a layer of Keratin-5-positive basal cells. We also found that the motile cilia are polarized coordinately and display a planar cell polarity. Surprisingly, we also found a region of multi-ciliated cells that line the posterior dorsal pole of the middle ear cavity which was previously thought to contain only non-ciliated cells. Our study provided a more complete understanding of cilia distribution and revealed for the first time coordinated polarity of cilia in the epithelium of the mammalian middle ear, thus illustrating novel structural features that are likely critical for middle ear functions and related to OM susceptibility.

Current major barriers for using next-generation sequencing (NGS) technologies in genetic mutation screening on an epidemiological scale appear to be the high accuracy demanded by clinical applications and high per-sample cost. How to achieve high efficiency in enriching targeted disease genes while keeping a low cost/sample is a key technical hurdle to overcome. We validated a cDNA-probe-based approach for capturing exons of a group of genes known to cause deafness. Polymerase chain reaction amplicons were made from cDNA clones of the targeted genes and used as bait probes in hybridization for capturing human genomic DNA (gDNA) fragments. The cDNA library containing the clones of targeted genes provided a readily available, low-cost, and regenerable source for producing capture probes with standard molecular biology equipment. Captured gDNA fragments by our method were sequenced by the Illumina NGS platform. Results demonstrated that targeted exons captured by our approach achieved specificity, multiplexicity, uniformity, and depth of coverage suitable for accurate sequencing applications by the NGS systems. Reliable genotype calls for various homozygous and heterozygous mutations were achieved. The results were confirmed independently by conventional Sanger sequencing. The method validated here could be readily expanded to include all-known deafness genes for applications such as genetic hearing screening in newborns. The high coverage depth and cost benefits of the cDNA-probe-based exon capture approach may also facilitate widespread applications in clinical practices beyond screening mutations in deafness genes.

Aims: To evaluate the influence of achieving secondary prevention target treatment goals for cardiovascular (CV) risk factors on clinical outcomes in patients with prior coronary artery bypass surgery (CABG). Methods and results: Accordingly, we analysed treatment to target goals in patients with prior CABG and atherothrombotic disease or known risk factors (diabetes, hypertension, hypercholesterolaemia, smoking, obesity) enrolled in the global REduction in Atherothrombosis for Continued Health (REACH) Registry, and their association with 1 year outcomes. A total of 13 907 of 68 236 patients (20.4%) in REACH had a history of prior CABG, and 1 year outcomes data were available for 13 207 of these. At baseline <25, 25-<50, 50-<75, and ≥75% risk factors were at goal in 3.7, 12.9, 31.7, and 51.7% of patients, respectively. One-year composite rates of CV death, non-fatal MI, non-fatal stroke were inversely related to the proportion of risk factors at goal at baseline (age, gender, and region adjusted rates 6.1, 5.6, 5.2, and 4.3% of patients with <25, 25-<50, 50-<75, and >75% risk factors at goal, respectively; P for trend 0.059). Conclusion: Risk-factor control varied greatly in CABG patients. Although CABG patients are frequently treated with appropriate therapies, these treatments fail to achieve an adequate level of prevention in many. This failure was associated with a trend for worse age-, gender-, and region-adjusted clinical outcomes. Thus, perhaps secondary prevention after CABG needs to focus on more comprehensive modification of risk factors to target goals in the hope of preventing subsequent CV events, and represents an opportunity to improve CV health. © The Author 2008.