Variants of OTOF and PJVK Genes in Chinese Patients with Auditory Neuropathy Spectrum Disorder

BACKGROUND: Mutations in OTOF and PJVK genes cause DFNB9 and DFNB59 types of hearing loss, respectively. The patients carrying pathogenic mutations in either of these genes may show the typical phenotype of auditory neuropathy spectrum disorder (ANSD). The aim of the present study was to identify OTOF and PJVK mutations in sporadic ANSD patients. METHODS AND FINDINGS: A total of 76 unrelated Chinese non-syndromic ANSD patients were sequenced on the gene OTOF and PJVK exon by exon. Variants were valued in 105 controls with normal hearing to verify the carrying rate. We identified one pathogenic mutation (c.1194T>A) and three novel, possibly pathogenic, variants (c.3570+2T>C, c.4023+1 G>A, and c.1102G>A) in the OTOF gene, and one novel, possibly pathogenic, variant (c.548G>A) in PJVK. Moreover, we found three novel missense mutations within the exons of OTOF. CONCLUSIONS: As we identified 4 and 1 possible pathogenic variants of the OTOF gene and the PJVK gene, respectively, we believe that screening in these genes are important in sporadic ANSD patients. The pathogenicity of these novel mutations needs further study because of their single heterozygous nature. Knowledge on the mutation spectra of these genes in Chinese would be beneficial in understanding the genetic character of this worldwide disease

Metabolic responses to high pCO2 conditions at a CO2 vent site in juveniles of a marine isopod species assemblage

We are starting to understand the relationship between metabolic rate responses and species' ability to respond to exposure to high pCO2. However, most of our knowledge has come from investigations of single species. The examination of metabolic responses of closely related species with differing distributions around natural elevated CO2 areas may be useful to inform our understanding of their adaptive significance. Furthermore, little is known about the physiological responses of marine invertebrate juveniles to high pCO2, despite the fact they are known to be sensitive to other stressors, often acting as bottlenecks for future species success. We conducted an in situ transplant experiment using juveniles of isopods found living inside and around a high pCO2 vent (Ischia, Italy): the CO2 'tolerant' Dynamene bifida and 'sensitive' Cymodoce truncata and Dynamene torelliae. This allowed us to test for any generality of the hypothesis that pCO2 sensitive marine invertebrates may be those that experience trade-offs between energy metabolism and cellular homoeostasis under high pCO2 conditions. Both sensitive species were able to maintain their energy metabolism under high pCO2 conditions, but in C. truncata this may occur at the expense of [carbonic anhydrase], confirming our hypothesis. By comparison, the tolerant D. bifida appeared metabolically well adapted to high pCO2, being able to upregulate ATP production without recourse to anaerobiosis. These isopods are important keystone species; however, given they differ in their metabolic responses to future pCO2, shifts in the structure of the marine ecosystems they inhabit may be expected under future ocean acidification conditions

Comparison of middle latency responses in presbycusis patients with two different speech recognition scores

Objective: The purpose of this study is to evaluate whether the middle latency responses (MLR) can be used for an objective differentiation of patients with presbycusis having relatively good (Group I) and relatively poor speech recognition scores (Group II)

Long-term outcome of neonatal hyperbilirubinaemia: subjective and objective audiological measures

Neonatal hyperbilirubinaemia is a common cause of early onset sensorineural hearing loss. There is no exact method to detect the extent of the neurotoxicity of bilirubin. On the other hand, the auditory pathway is known to be one of the most sensitive parts of the central nervous system (CNS) to this toxic agent. This prospective follow-up study was performed to evaluate and compare the factors related to the hearing of neonates with severe hyperbilirubinaemia and an age-matched control group. Both of these groups were tested using auditory brainstem response (ABR) as well as evoked otoacoustic emissions. Additionally, both of these groups of children were evaluated subjectively using an early speech-language-communication evaluation questionnaire. There was no significant difference in either objective (ABR and evoked otoacoustic emission) or subjective assessment (questionnaire) between the study and control groups. Furthermore, no correlation between serum total bilirubin levels and ABR latencies or thresholds was found within the study group

Results of multiple-frequency tympanometry measures in normal and otosclerotic middle ears

WOS: 000260085800003PubMed ID: 18923983Tympanometry is a non-invasive, quick, and inexpensive method for examining the middle-ear function. Its limited value in differentiating otosclerotic from normal middle ears caused researchers to develop new methods for evaluation of middle ears. Resonant frequency had been found to be higher in otosclerotic middle ears than normals. We conducted multiple-frequency tympanometry measurements in 25 surgically confirmed otosclerotic ears and 100 normal ears. Mean middle-ear resonant frequency for the otosclerotic group was found to be 1190 Hz and mean middle-ear resonant frequency of the control group was 934.6 Hz (p <0.001). With a cut off value of 1025 Hz (based on 95% confidence interval), sensitivity was 80% and specificity was 82%. The present findings confirm the advantage of the resonant frequency estimation over conventional tympanometry in detecting middle-ear status and mechanics in patients with otosclerosis. As a conclusion, detecting resonant frequency when evaluating patients for otosclerosis must be an essential part of examination. Nevertheless, further investigation is necessary for better diagnosis of otosclerosis preoperatively

Features of unilateral hearing loss detected by newborn hearing screening programme in different regions of Turkey

PubMedID: 23099038Objective: Newborn hearing screening (NHS) works well for babies with bilateral hearing loss. However, for those with unilateral loss, it has yet to be established some standard rules like age of diagnose, risk factors, hearing loss degree. The aim of this study is to identify the demographic characteristics of newborns with unilateral hearing loss to obtain evidence based data in order to see what to be done for children with unilateral hearing loss (UHL). Method: Newborn hearing screening data of 123 babies with unilateral hearing loss, 71 (57.7%) male and 52 (42.3%) female, were investigated retrospectively. Data provided from the archives of six referral tertiary audiology centers from four regions in Turkey. Data, including type of hearing loss; age of diagnosis; prenatal, natal and postnatal risk factors; familial HL and parental consanguinity was analyzed in all regions and each of the Regions 1-4 separately. Result: The difference between data obtained in terms of gender and type of hearing loss was detected as statistically significant (p0.05). Diagnosis procedure was completed mostly at 3-6 months in Region 4; whereas, in other regions (Regions 1-3), completion of procedure was delayed until 6 months-1 year. Conclusion: This study indicates that the effect of postnatal risk factors, i.e. curable hyperbilirubinemia, congenital infection and intensive care is relatively high on unilateral hearing loss, precautions should be taken regarding their prevention, as well as physicians and other health personnel should be trained in terms of these risks. For early and timely diagnosis, families will be informed about hearing loss and NHS programme; will be supported, including financial support of diagnosis process. By dissemination of the NHS programme to the total of country by high participation rate, risk factors can be determined better and measures can be increased. Additionally, further studies are needed with more comprehensive standard broad data for more evidence based consensus. © 2012 Elsevier Ireland Ltd

Regional differences of Turkey in risk factors of newborn hearing loss

PubMedID: 29106875Objective The aim of this study was to discover Turkish regional differences in the risk factors of newborn hearing loss. Method A multi-centered retrospective design was used. A total of 443 children, registered to the national newborn hearing screening programme, with bilateral hearing loss, from five different regions of Turkey, were evaluated in terms of the types of hearing loss, the degree of hearing loss, the types of risk factors, parental consanguinity, age at diagnosis and age of auditory intervention, respectively. Results There was no significant difference in the prevalence of hearing loss between regions (?2 = 3.210, P = 0.523). Symmetric Sensorineural Hearing Loss (SSHL) was the most common type of HL in all regions (91.8%). Profound HL was the most common degree of HL in all regions (46.2%). There were statistically significant differences between regions in terms of types of HL (?2 = 14.151, P = 0.000). As a total, 323 (72.9%) of subjects did not have any risk factors. There were statistically significant differences between regions in terms of the types of risk factors (pre, peri and post-natal) for SSNHL (?2 = 16.095, P = 0.000). For all regions, the age of diagnosis was convenient with the JCIH criteria. However the age of hearing aid application was prolonged in some regions. There were statistically significant differences between regions in terms of the age of diagnosis (?2 = 93.570, P = 0.000) and the age of auditory intervention (?2 = 47.323, P = 0.000). The confounding effects of gender, age of diagnosis, age of hearing aids applications, HL in the family, types of risk factors for HL on SSNHL were detected. Conclusion To reach the goal of a high quality newborn hearing screening, there is a need to develop an evidence-based standard for follow up guideline. In addition, risk factors should be re-evaluated according to regional differences and all regions should take their own precautions according to their evidence based data. © 2017 Elsevier B.V