The ClC-K channels
and
are crucial for the transepithelial transport processes required for sufficient urinary concentrations and sensory mechanoelectrical transduction in the cochlea. ...Loss-of-function alleles in these channels are associated with various clinical phenotypes, ranging from hypokalemic alkalosis to sensorineural hearing loss (SNHL) accompanied by severe renal conditions, i.e., Bartter's syndrome. Using a stepwise genetic approach encompassing whole-genome sequencing (WGS), we identified one family with compound heterozygous variants in the ClC-K channels, specifically a truncating variant in
in trans with a contiguous deletion of
and
. Breakpoint PCR and Sanger sequencing elucidated the breakpoint junctions derived from WGS, and allele-specific droplet digital PCR confirmed one copy loss of the
_
contiguous deletion. The proband that harbors the
variants is characterized by SNHL without hypokalemic alkalosis and renal anomalies, suggesting a distinct phenotype in the ClC-K channels in whom SNHL predominantly occurs. These results expanded genotypes and phenotypes associated with ClC-K channels, including the disease entities associated with non-syndromic hearing loss. Repeated identification of deletions across various extents of
suggests a mutational hotspot allele, highlighting the need for an in-depth analysis of the
intergenic region, especially in undiagnosed SNHL patients with a single hit in
.
The cortical auditory evoked potential (CAEP)-based P1 component acts as a biomarker for cochlear implantation (CI) outcomes in children with auditory neuropathy spectrum disorder (ANSD). To date, ...early intervention primarily before the age of two years and six months of CI usage is necessary and sufficient to achieve age-appropriate cortical maturation and good prognosis. However, varying degrees of neural dyssynchrony, resulting from the etiological heterogeneity of ANSD, may preclude uniform application of this hypothesis to ensure auditory cortical maturation. Thus, a focused evaluation of those carrying
OTOF
variants, which may be the salient molecular etiology of prelingual ANSD, would circumvent the issue of heterogeneity. Here, we sought to provide a much better understanding of the brain perspectives (i.e., P1 maturation) in
OTOF
-associated ANSD subjects and set the stage for an optimal strategy to enhance language development. We conducted a preliminary study comprising 10 subjects diagnosed with
OTOF
-related ANSD who underwent CI by a single surgeon and subsequently underwent measurements of the P1 component. We observed that DFNB9 subjects who received CI after 2 years of age exhibited “absent” or “anomalous” P1 components that correspond to delayed language development. However, timely implantation, as early as 12 months of age
per se
, might be insufficient to achieve age-appropriate cortical maturation of DFNB9 in cases with six to seven months of device use. This suggests the importance of sustained rehabilitation in DFNB9 than in other etiologies. Indeed, an additional follow-up study showed that a reduction in P1 latency was linked to an improvement in auditory performance. Collectively, our results suggest that central auditory maturation and successful outcome of CI in DFNB9 may have more demanding requirements, that is, earlier implantation and more sustained rehabilitation. We believe that the current study opens a new path toward genome-based neuroimaging in the field of hearing research.
Along with phantom pain, tinnitus, a phantom auditory perception occurring in the absence of an external acoustic stimulus, is one of the most representative phantom perceptions that develops in ...subjects with decreased peripheral sensory input. Although tinnitus is closely associated with peripheral hearing loss (HL), it remains unclear why only some individuals with HL develop tinnitus. In this study, we investigated the differences between 65 HL with tinnitus (HL‐T) and 104 HL with no tinnitus (HL‐NT) using a resting‐state electroencephalography data‐based volume entropy model of the brain network, by comparing the afferent node capacities, that quantify the contribution of each node to the spread of information, of all Brodmann areas. While the HL‐T group showed increased information flow in areas involved in Bayesian inference (the left orbitofrontal cortex, the left subgenual anterior cingulate cortex, and the left ventrolateral prefrontal cortex) and auditory memory storage (the right hippocampus/parahippocampus), the HL‐NT group showed increased afferent node capacity in hub areas of the default mode network (DMN; the right posterior cingulate cortex and the right medial temporal gyrus). These results suggest that the balance of activity between the Bayesian inferential network (updating missing auditory information by retrieving auditory memories from the hippocampus/parahippocampus) and DMN (maintaining the “silent status quo”) determines whether phantom auditory perception occurs in a brain with decreased peripheral auditory input.
Although tinnitus is closely associated with peripheral hearing loss (HL), it remains unclear why only some individuals with HL develop tinnitus. We have found that the balance of activity between the Bayesian inferential network (updating missing auditory information by retrieving auditory memories from the hippocampus/parahippocampus) and DMN (maintaining the “silent status quo”) determines whether phantom auditory perception occurs in a brain with decreased peripheral auditory input.
Novel hearing loss (HL) genes are constantly being discovered, and evidence from independent studies is essential to strengthen their position as causes of hereditary HL. To address this issue, we ...searched our genetic data of families with autosomal dominant HL (ADHL) who had been tested with high-throughput DNA sequencing methods. For
CD164
, only one pathogenic variant in one family has so far been reported. For
LMX1A
, just two previous studies have revealed its involvement in ADHL. In this study we found two families with the same pathogenic variant in
CD164
and one family with a novel variant in
LMX1A
(c.686C>A; p.(Ala229Asp)) that impairs its transcriptional activity. Our data show recurrence of the same
CD164
variant in two HL families of different geographic origin, which strongly suggests it is a mutational hotspot. We also provide further evidence for haploinsufficiency as the pathogenic mechanism underlying
LMX1A
-related ADHL.
Objectives/Hypothesis
Pregnancy‐induced systemic physiological changes appear to be associated with reversible hearing changes in pregnant/postpartum women. However, most studies are case reports due ...to the rare occurrence of sudden sensorineural hearing loss (SSNHL) during pregnancy. We aimed to evaluate the risk of SSNHL during the pregnancy and postpartum periods.
Study Design
A longitudinal case‐control study using a nationwide population cohort.
Methods
Using the Korean National Health Insurance Review and Assessment Service, we collected data from 63,331 pregnant/postpartum participants who were matched 1:2 by age, income, region of residence, and medical history with 126,662 control participants. We included participants who had International Classification of Diseases, 10th Revision (ICD‐10) codes indicating delivery (O80–O84). For SSNHL (ICD‐10 code H91.2), we included only those participants who underwent audiometry and were treated with steroids. The incidence of SSNHL was measured for the periods corresponding to pregnancy (conception through delivery) up to 1 year postpartum in the pregnant participants.
Results
During the pregnancy period, the SSNHL rate was not higher (19.5 per 100,000) compared with the control group (60.7 per 100,000). The adjusted odds ratio of SSNHL during pregnancy was 0.32 (95% confidence interval: 0.16‐0.65, P = .002). The SSNHL rate during the postpartum period (37.9 per 100,000) was similar to that of the control group (36.3 per 100,000). The adjusted odds ratio of SSNHL during the postpartum period was 1.04 (95% confidence interval: 0.64‐1.71, P = .867). The risk of SSNHL in the patients during the pregnancy/postpartum period was not higher than that in controls, regardless of age and specific subperiod.
Conclusions
The pregnant and postpartum women were not at higher risk of SSNHL.
Level of Evidence
NA
Laryngoscope, 130:E237–E242, 2020
Hearing loss affects some nutrient intake. Disabling hearing loss may exacerbate these issues. We aimed to evaluate nutrient intake and assess deficiencies based on functional hearing status. The ...study included 6907 participants with information on demographic factors, nutrient intake, weight, height, disease status, and hearing level in the eighth Korea National Health and Nutrition Examination Survey, conducted from 2019 to 2021. We categorized the participants into 3 groups based on their functional hearing status: bilateral hearing, unilateral hearing, and disabling hearing loss. The disabling hearing loss group showed lower intake of most major nutrients (P < 0.05), dietary fiber (P < 0.001), and most minerals and vitamins (P < 0.05), with some insufficiencies. The unilateral hearing group showed lower intake only for potassium (P = 0.036) compared to the bilateral hearing group and significantly higher intake of hydration (P = 0.039), dietary fiber (P = 0.039), and calcium (P = 0.009) than the disabling hearing loss group. Nutrient insufficiency in the disabling hearing loss group was more prominent in women, and was partially resolved by using hearing aids. Clinicians and nutritionists should consider undernourishment in these patients, and appropriate interventions for nutrition and hearing aids should be recommended.
There are still debates about timing and effectiveness of cochlear implants (CI) in pediatric subjects with significant residual hearing who do not belong to traditional indication of CI. In this ...study, we aimed to investigate the outcomes of CI, specifically on improvement of pronunciation, among hearing-impaired children already with a substantial degree of language skills as evaluated by Categories of Auditory Perception (CAP) scores or sentence score. Our cohort comprised pediatric CI recipients from July 2018 through October 2020. Among them, cases with CAP scores of 5 or 6 preoperatively were defined as "borderline cases". We investigated prevalence and etiologies, and compared speech evaluation data preoperatively and postoperatively at three time points (3, 6 and 9-12 months after implantation). Among 86 pediatric CI recipients, 13 subjects (15.12%) had language development that reached CAP scores of 5 or 6 before implantation. Postoperative speech evaluation data 6 months after implantation revealed significant improvement of pronunciation (Urimal Test of Articulation and Phonation scores: UTAP), Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS) and word perception scores, but not of CAP and sentence perception scores. Notably, the significant improvement of pronunciation based on UTAP scores outstripped that of other speech parameters and this continued steadily up to one-year postoperatively. The result of the study serves as evidence for what to expect from cochlear implantation in hearing-impaired children who have already achieved a substantial degree of language development in terms of CAP scores or sentence perception scores, preoperatively.
LMX1A, encoding the LIM homeobox transcription factor, is essential for inner ear development. Despite previous reports of three human LMX1A variants with nonsyndromic hearing loss (NSHL) in the ...literature, functional characterization of these variants has never been performed. Encouraged by identification of a de novo, heterozygous, missense variant (c.595A > G; p.Arg199Gly) located in the homeodomain of LMX1A in a subject with congenital severe‐to‐profound deafness through Exome sequencing, we performed luciferase assay to evaluate transcriptional activity of all LMX1A variants reported in the literature including p.Arg199Gly. Resultantly, p.Arg199Gly manifesting the most severe NSHL showed the biggest reduction of transcriptional activity in contrast with moderately reduced activity of p.Cys97Ser and p.Val241Leu associated with less severe progressive NSHL, proposing a genotype–phenotype correlation. Further, our dominant LMX1A variant exerted pathogenic effects via haploinsufficiency rather than dominant‐negative effect. Collectively, we provide a potential genotype–phenotype correlation of LMX1A variants as well as the pathogenic mechanism of LMX1A‐related NSHL.
Although the Great Spotted Woodpecker Dendrocopos major and Grey-headed Woodpecker Picus canus have overlapping ranges in South Korea, they occur in areas with different forest structures and the ...occurrence of each species is associated with their main foods.
To investigate the biotic factors related to the occurrence of the Great Spotted Woodpecker and the Grey-headed Woodpecker, two species that frequently inhabit overlapping regions in South Korea.
Correlations between the occurrence of the two woodpecker species, forest characteristics, and bird and insect species richness were evaluated based on large-scale public data from the National Ecosystem Survey and a Forest Type Map.
The occurrence of Great Spotted Woodpeckers was associated with forest stands with at least 75% coniferous trees, whereas the occurrence of Grey-headed Woodpeckers was negatively associated with forested areas with canopy cover exceeding 50%. The occurrence of both species was strongly and positively correlated with the species richness of forest birds. The occurrence of Great Spotted Woodpeckers was correlated with the species richness of Coleoptera, while that of the Grey-headed Woodpecker was correlated with the species richness of Hymenoptera and Diptera.
The co-occurrence of the two woodpecker species within shared habitats can be explained by low competition due to differences in preferred forest characteristics and in the food sources used by each species.
In large greenhouses with information and communication technology capability, environmental conditions can be measured and communicated to control the internal environment. However, in such ...greenhouses, it is difficult to control the internal environment uniformly and appropriately. Additionally, there is uncertainty regarding whether the data measured at a particular location accurately represents the entire greenhouse environment. Furthermore, the locations of sensors are usually determined based on the experience of growers and the greenhouse designers. To accurately measure the internal environment of a greenhouse, it is necessary to properly select the installation locations of the sensors. The objective of this study was to determine the optimal sensor placement for monitoring and controlling the internal environment of a greenhouse. The study greenhouse was an eight-span plastic greenhouse growing Irwin mango crops. Air temperature data measured at nine locations in the greenhouse were used. All of the possible combinations of monitoring locations were evaluated, and optimal sensor placements were selected according to the number of sensors. The optimisation was conducted using two methods: error-based sensor placement and entropy-based sensor placement. Using the former approach, sensor locations for which the monitored data were close to the reference value, i.e. the average data of all the measurement locations, were selected. Using the latter approach, sensor locations influenced by the external weather conditions resulting in poor environmental control were selected. Using these methods, optimal sensor locations for representing the entire environment of the facility and for detecting areas with significant air temperature variations were determined.
•Optimal sensor locations were evaluated for monitoring and controlling the internal environment of a greenhouse.•An error-based method and entropy-based method were used to determine the optimal sensor locations.•The optimal sensor locations were selected based on the number of sensors.
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