[Mutation spectrum analysis of 23-site chip neonatal deafness genetic screening]

Objective:To analyze the mutation spectrum of 23-site chip newborn deafness genetic screening in Beijing, and to provide basis for genetic counseling and clinical diagnosis and treatment. Methods:The study included 21 006 babies born in Beijing from December 2022 to June 2023. All subjects underwent newborn deafness genetic screening in Beijing Tongren Hospital, covering 23 variants in 4 genes, the GJB2 gene（c.35delG, c.176_191del16, c.235delC, c.299_300delAT, c.109G>A, c.257C>G, c.512insAACG, c.427C>T, c.35insG）, SLC26A4 gene（c.919-2A>G, c.2168A>G, c.1174A>T, c.1226G>A, c.1229C>T, c.1975G>C, c.2027T>A, c.589G>A, c.1707+5G>A, c.917insG, c.281C>T）, Mt12SrRNA（m.1555A>G, m.1494C>T） and GJB3 gene（c.538C>T）. The mutation detection rate and allele frequency were analyzed. Results:The overall mutation detection rate was 11.516%（2 419/21 006）, with the GJB2 gene being the most frequently involved at 9.097%（1 911/21 006）, followed by the SLC26A4 gene at 2.123%（446/21 006）, the GJB3 gene at 0.362%（76/21 006） and Mt12SrRNA at 0.176%（37/21 006）. Among the GJB2 genes, c.109G>A and c.235delC mutation detection rates were the highest, with 6.579%（1 382/21 006） and 1.795%（377/21 006）, respectively. Of the SLC26A4 genes, c.919-2A>G and c.2168A>G had the highest mutation rates of 1.423%（299/21 006） and 0.233%（49/21 106）, respectively. Regarding the allele frequency, GJB2 c.109G>A was the most common variant with an allele frequency of 3.359%（1 411/42 012）, followed by the GJB2 c.235delC at 0.897%（377/42 012） and the SLC26A4 c.919-2A>G at 0.719%（302/42 012）. Conclusion:23-site chip newborn deafness genetic screening in Beijing showed that GJB2 c.109G>A mutation detection rate and allele frequency were the highest. This study has enriched the epidemiological data of 23-site chip genetic screening mutation profiles for neonatal deafness, which can provide evidence for clinical practice.

Factors that influence health service access in deaf and hard-of-hearing children: a narrative review

OBJECTIVES

Early diagnosis and intervention of deaf and hard-of-hearing (DHH) children leads to improved language and psychosocial outcomes. However, many child, parent and provider related factors can influence access to early intervention services, including hearing devices. This narrative review aims to explore factors that influence health service access in DHH children.

DESIGN

A systematic search was conducted to identify articles that explored factors that influenced health service access in DHH children in countries with Universal Newborn Hearing Screening, published between 2010 and 2022.

STUDY SAMPLES

Fifty-nine articles met the inclusion criteria for data extraction. This included 4 systematic reviews, 2 reviews, 39 quantitative and 5 mixed methods studies and 9 qualitative studies.

RESULTS

The identified factors were grouped into the following themes: (a) demographic factors, (b) family related factors, (c) child related factors, (d) factors specific to hearing devices, (e) service delivery, f) telehealth and (g) COVID-19.

CONCLUSION

This review provided a comprehensive summary of multiple factors that affect access to health services in DHH children. Psychosocial support, consistent clinical advice, allocation of resources to rural communities and use of telehealth are possible ways to address barriers and improve health service access.

Hearing Loss: Genetic Testing, Current Advances and the Situation in Latin America

Congenital hearing loss is the most common birth defect, estimated to affect 2-3 in every 1000 births, with ~50-60% of those related to genetic causes. Technological advances enabled the identification of hundreds of genes related to hearing loss (HL), with important implications for patients, their families, and the community. Despite these advances, in Latin America, the population with hearing loss remains underdiagnosed, with most studies focusing on a single locus encompassing the GJB2/GJB6 genes. Here we discuss how current and emerging genetic knowledge has the potential to alter the approach to diagnosis and management of hearing loss, which is the current situation in Latin America, and the barriers that still need to be overcome.

A novel method for detecting nine hotspot mutations of deafness genes in one tube

Deafness is a common sensory disorder. In China, approximately 70% of hereditary deafness originates from four common deafness-causing genes: GJB2, SLC26A4, GJB3, and MT-RNR1. A single-tube rapid detection method based on 2D-PCR technology was established for nine mutation sites in the aforementioned genes, and Sanger sequencing was used to verify its reliability and accuracy. The frequency of hotspot mutations in deafness genes was analysed in 116 deaf students. 2D-PCR identified 27 genotypes of nine loci according to the melting curve of the FAM, HEX, and Alexa568 fluorescence channels. Of the 116 deaf patients, 12.9% (15/116) carried SLC26A4 mutations, including c.919-2A > G and c.2168A > G (allele frequencies, 7.3% and 2.2%, respectively). The positivity rate (29.3%; 34/116) was highest for GJB2 (allele frequency, 15.9% for c.235delC, 6.0% for c.299_300delAT, and 2.6% for c.176-191del16). Sanger sequencing confirmed the consistency of results between the detection methods based on 2D-PCR and DNA sequencing. Common pathogenic mutations in patients with non-syndromic deafness in Changzhou were concentrated in GJB2 (c.235delC, c.299_300delAT, and c.176-191del16) and SLC26A4 (c.919-2A > G and c.2168 A > G). 2D-PCR is an effective method for accurately and rapidly identifying deafness-related genotypes using a single-tube reaction, and is superior to DNA sequencing, which has a high cost and long cycle.

Analysis of deafness susceptibility gene of neonates in northern Guangdong, China

This study aimed to explore the molecular epidemiology characteristics of deafness susceptibility genes in neonates in northern Guangdong and provide a scientific basis for deafness prevention and control. A total of 10,183 neonates were recruited between January 2018 and December 2022 at Yuebei People's Hospital. Among these, a PCR hybridization screening group of 8276 neonates was tested for four deafness genes: GJB2, SLC26A4, mtDNA, and GJB3 by PCR hybridization. Another group used next-generation sequencing (NGS) to detect genetic susceptibility genes in 1907 neonates. In PCR hybridization screening group, 346 (4.18%) of 8276 neonates were found to be carriers of the deafness gene. Among these, 182 (2.2%) had GJB2 variants, 114 (1.38%) had SLC26A4 variants, 35 (0.42%) had mtDNA variants, and 15 (0.18%) had GJB3 variants. In NGS Screening Group, 195 out of 1907 neonates were found to be carriers of the deafness gene, with a positive rate of 10.22%. Among these, 137 (7.18%) had GJB2 variants, 41 (2.15%) had SLC26A4 variants, 11 (0.58%) had mtDNA variants, and 6 (0.31%) had GJB3 variants. The prevalence of deafness gene variants was high in Northern Guangdong Province. The most common gene for deafness was GJB2, followed by SLC26A4 and mtDNA. GJB3 variants are rare. Compared with PCR hybridization method, NGS technology can expand the screening scope and greatly improve the detection rate of deafness genes. The c.109G>A of GJB2 was found to occur at a high frequency, which should be considered. Therefore, it is important to conduct neonatal deafness gene screening to prevent and control hereditary deafness.

Next-generation sequencing for genetic testing of hearing loss populations

BACKGROUND AND AIMS

Hearing loss is a common sensorineural disease with genetic heterogeneity. More than 140 genes are known to cause hereditary hearing loss. We aim to uncover the etiologies of hearing loss and provide patients with reasonable reproductive choices.

MATERIALS AND METHODS

Total 825 participants were recruited, including 74 individuals, 47 couples, and 219 families, to identify the molecular etiologies of hearing loss using next-generation sequencing (NGS). Novel mutations were verified with a minigene splicing assay and the construction of three-dimensional protein models.

RESULTS

A positive molecular diagnosis was obtained for 244 patients, a rate of 63.05 %. Total 470 mutations were identified in 18 causative genes in positive patients. The most common genes mutated were GJB2 and SLC26A4. 47 novel mutations were identified. Further analysis predicted that two splicing mutations would cause abnormal mRNA splicing and three missense mutations would affect the protein structure. The results of prenatal diagnosis showed that the genotypes of 15 fetuses were the same as the probands.

CONCLUSION

Our findings expand the mutation spectrum of hearing loss and highlight the importance of genetic diagnosis and prenatal diagnosis to allow accurate and personalized guidance for those at high risk of deafness.

Mutation analysis of GJB2, SLC26A4, GJB3 and mtDNA12SrRNA genes in 251 non-syndromic hearing loss patients in Fujian, China

OBJECTIVES

The molecular etiology of non-syndromic hearing loss (NSHL) in Southeastern China (Fujian) has not been precisely identified. our study selected patients with NSHL and analyzed their causative genes, which helped to improve the accuracy of the diagnosis of hereditary hearing loss (HHL) and its treatment.

METHODS

251 unrelated patients who attended the otolaryngology clinic of Fujian Maternal and Child Health Hospital with hearing loss were enrolled to our study. All patients had genetic tests and listening tests, of which 251 were diagnosed with NSHL. In addition, we used whole-exome sequencing (WES) in a patient who has a significant family history of HHL but negative for gene chip testing, as well as in his family members.

RESULT

Among of 251 patients, Nucleotide changes were found in 63 cases (25.09%), including 34 located in GJB2(13.5%, including 235delC and 299_300delAT), 13 located in SLC26A4(5.18%, including c.919-2G > A and 2168 A > G), 1 located in GJB3(0.4%,538C > T) and 16 located in mtDNA12SrRNA (6.37%,1555 A > G). In addition, we discuss the process of identifying novel PLS1 mutations from 251 patients.

CONCLUSION

Our results demonstrate the conventional deafness gene mutation in 251 NSHL patients in Fujian, China. Compared with the other area of China, we have a lower detection rate, but GJB2 235delC remains the most common mutation in Fujian. In addition, we discuss the process of discovering novel mutation locus for deafness, which provides an understanding for deafness diagnosis and genetic testing.

Longitudinal Analysis of Early Hearing Detection and Intervention Program Performance

OBJECTIVES

Early hearing detection and intervention (EHDI) is a newborn hearing screening system created to detect infants with hearing loss (HL) and intervene to reduce language and communication impairment. Early hearing detection (EHD) consists of three sequential stages: identification, screening, and diagnostic testing. This study longitudinally reviews each stage of EHD in each state and proposes a framework to improve utilization of EHD data.

DESIGN

A retrospective public database review was conducted, accessing publicly available data from the Centers for Disease Control and Prevention. Summary descriptive statistics were utilized to generate a descriptive study of EHDI programs in each U.S. state from 2007 to 2016.

RESULTS

Data over 10 years from 50 states as well as Washington, DC were included in this analysis, creating up to 510 data points per analysis. Hundred percent (85 to 105) (median [min to max]) of newborns were identified by and entered EHDI programs. Ninety-eight percent (51 to 100) of identified infants completed screening. Of the infants who screened positive for HL, the proportion that received diagnostic testing was 55% (1 to 100). The overall proportion of infants who failed to complete EHD was 3% (1 to 51). Of the infants who fail to complete EHD 70% (0 to 100) are from missed screenings, 24% (0 to 95) are from missed diagnostic testing, and 0% (0 to 93) are from missed identification. Although there are more infants missed at screening, it was estimated, with limitations, that there is an order of magnitude more infants with HL among those who did not complete diagnostic testing compared with those who did not complete screening.

CONCLUSIONS

Analysis demonstrates high completion rates at both identification and screening stages, whereas the diagnostic testing stage demonstrates low and highly variable completion rates. The low completion rates at diagnostic testing create a bottleneck in the EHD process and the large variability impedes the comparison of HL outcomes across states. Analysis also demonstrates that among all stages of EHD, whereas the largest number of infants are missed at screening, the largest number of children with HL are likely missed at diagnostic testing. Therefore, a focus by individual EHDI programs on addressing causes of low diagnostic testing completion rates would yield the greatest increase in the identification of children with HL. Potential causes of low diagnostic testing completion rates are further discussed. Finally, a new vocabulary framework is proposed to facilitate further study of EHD outcomes.

A cost-effectiveness analysis of pre-pregnancy genetic screening for deafness: an empirical study in China

Objectives

This research aims to assess the effectiveness and cost-effectiveness of pre-pregnancy deafness screening policies.

Methods

Married couples from Shanghai, Beijing, and Suzhou in China were enrolled. We conducted high-throughput, pre-pregnancy genetic screenings for deafness in women and their partners. We compared the cost-effectiveness of deafness genetic screening with the status quo. The two-step screening (wife then partner) and following treatments and interventions were included in the decision tree model. We conducted a cost-effectiveness analysis based on the decrease in deaf newborns, healthy newborn births, and cost-utility analysis of pre-pregnancy deafness genetic screening separately. Cost, utility, and probability data used in the three models were collected from a survey combined with literature and expert consultants. A 5% discount rate and a series of one-way sensitivity analyses along with a Monte Carlo simulation were used to test the reliability of this research.

Results

Between Jan 1, 2019, and Dec 31, 2021, we recruited 6,200 females and 540 male spouses from community health service centers in Shanghai, Beijing, and Suzhou. The incremental cost-effectiveness ratio (ICER) for reducing deaf newborn births was USD 32,656 per case and USD 1,203,926 per case for increasing one healthy newborn birth. This gap exists because of the overall decrease of newborn births. From the perspective of the whole society, deafness genetic screening is not cost-effective for reducing the overall quality-adjusted life years (QALY) in the population.

Discussion

Pre-pregnancy genetic testing is effective in decreasing the occurrence of congenital deafness. It is a cost-saving measure when compared with the costs of future medical expenditure and income loss for the affected families. However, such screening and preventive avoidance of pregnancy will decrease the population size and QALY. Only post-screening ART with PGT was shown to increase the birth of healthy newborns. Focusing on key groups such as premature births or consanguineous couples may improve the societal effects of screening.

Assessing Autism in Deaf/Hard-of-Hearing Youths: Interdisciplinary Teams, COVID Considerations, and Future Directions

Autism spectrum disorders are more prevalent in children who are Deaf or Hard of Hearing (D/HH) than in the general population. This potential for diagnostic overlap underscores the importance of understanding the best approaches for assessing autism spectrum disorder in D/HH youths. Despite the recognition of clinical significance, youths who are D/HH are often identified as autistic later than individuals with normal hearing, which results in delayed access to appropriate early intervention services. Three primary barriers to early identification include behavioral phenotypic overlap, a lack of "gold-standard" screening and diagnostic tools for this population, and limited access to qualified clinicians. In the current article, we seek to address these barriers to prompt an appropriate identification of autism by providing recommendations for autism assessment in children who are D/HH from an interdisciplinary hearing and development clinic, including virtual service delivery during COVID-19. Strengths, gaps, and future directions for implementation are addressed.

Postnatal genetic umbilical cord analysis for earliest possible detection of inherited hearing impairment

INTRODUCTION

The most common sensorineural disorder in humans is hearing impairment and approximately 60% of prelingual hearing disorders are genetic. Especially parents with a congenital deaf child want to know as early as possible whether their second born child has the same genetic defect or not. The aim of this study is to demonstrate that postnatal genetic umbilical cord analysis is both the earliest detection possibility and sufficient.

METHODS

We included first born children with severe hearing impairment that underwent cochlear implantation. All included patients were analyzed genetically and exhibited mutations of either DFNB1 loci or SLC26A4 gene. Additionally, the umbilical cord of the sibling underwent genetic analysis to detect hereditary genetic mutations as early as possible.

RESULTS

49 newborn children out of 22 families were included in this study. Genetic analysis revealed clinical relevant mutations in all first born children and in four siblings via umbilical cord analysis. All patients who have been diagnosed with a relevant genetic mutation that caused severe hearing impairment underwent hearing rehabilitation via cochlear implant surgery.

CONCLUSION

This study demonstrates the sufficient and early as possible detection of known genetically hearing disorders via umbilical cord analysis. In case of a known familial genetic hearing disorder, it is advisable to analyze newborn siblings for the corresponding genetic defect as soon as possible, to be able to plan and initiate clinical care for the patient as early as possible. It is also extremely important for the parents to obtain clear information about the auditory status of the newborn.

Identification a novel pathogenic LRTOMT mutation in Mauritanian families with nonsyndromic deafness

PURPOSE

Although recessive mutations in GJB2 are the common genetic etiology of sensorineural hearing impairment (SNHI), variants in LRTOMT gene were also identified, mostly in Middle East and North African populations.

METHODS

Using Sanger sequencing we screened the exon 7 of LRTOMT in a cohort of 128 unrelated Mauritanian children with congenital deafness.

RESULTS

Only one biallelic missense mutation, predicted as pathogenic (c.179 T > C;p.Leu60Pro) was found at homozygous state in four families. This variant, not reported before, showed a deleterious effect by SIFT (score: 0.01) and a disease-causing effect by Mutation Taster (prob: 1). Exploration of the encoded protein 3D structure revealed a disruption from an organized α helix (in the normal protein structure) into a random conformation. Early fitting of a cochlear implant seemed to improve the audition ability of the mutation carrier.

CONCLUSION

Further screening using a panel of deafness genes may expose other variants underlying hearing impairment in our population.

Audiological profile of deaf and hard-of-hearing children under six years old in the "HI HOPES cohort" in South Africa (2006-2011)

BACKGROUND

This study concerns deaf children under six years in the South African HI HOPES Cohort.

OBJECTIVE

To examine their audiological profile, aetiological risk factors for infant hearing loss as well as the relationship between identification, amplification and socio-economic influences.

DESIGN

Using a cohort design, secondary data analysis of a pre-existing dataset demonstrated adequate representation of South African demographic characteristics.

STUDY SAMPLE

A total of 532 deaf and hard-of-hearing infants enrolled in the HI HOPES early intervention programme in three provinces (2006-2011).

RESULTS

The median age of identification of children with bilateral hearing loss (n = 502) was 24.0 months (IQR = 12-36 months). Infants with aetiological risk factors were identified later than those without risk factors, and the latest age of identification (28.5 months) was for those with three aetiological risk factors (n = 42). The median age of amplification was 32 months with 102 children eligible for amplification at 31.1 months still unamplified. Early identification did not imply early amplification, and the more economically advantaged a Province the smaller the gap between ages of identification and amplification.

CONCLUSIONS

In a field with little population-level evidence, the size, and representativeness of this dataset makes a significant contribution to our understanding of infant hearing loss in South Africa.

Case report: mitochondrial diabetes mellitus in a Chinese family due to m.3243A>G

OBJECTIVES

Mitochondrial diabetes mellitus is caused by dysfunctional mitochondria and is often misdiagnosed because of its various clinical manifestations. It's even rarer in children, and without a clear family history of diabetes with hearing loss, it's often difficult to diagnose.

CASE PRESENTATION

This is a case study of a family with maternally inherited diabetes mellitus and deafness (MIDD). The proband was an adolescent girl with diabetes with a family history of type 2 diabetes (T2DM) for three generations. Family members have undetected hearing impaired. The proband could not be diagnosed with type 1 diabetes (T1DM) or T2DM. Therefore, whole exome and mitochondrial gene sequencing was performed, which identified an m.3243A>G mutation in the mitochondrial DNA.

CONCLUSIONS

This suggests that we should be alert to the possibility of hereditary diabetes, especially mitochondrial diabetes in patients with atypical diabetes. A thorough physical examination is very important. What is new: (1) Mitochondrial diabetes in childhood may not be accompanied by deafness even with highly heteroplasmy levels. (2) In MIDD patients, sometimes hearing loss cannot be perceived, which requires us to conduct detailed physical examinations and related examinations. (3) The use of metformin in MIDD patients did not have adverse consequences.

The Effect of Universal Newborn Hearing Screening on Spoken Language after Cochlear Implantation

BACKGROUND

The universal newborn hearing screening (UNHS) was fully implemented across New Zealand by 2010 to improve outcomes for children with prelingual deafness. A previous audit undertaken by our center, the Southern Cochlear Implant Programme (SCIP), demonstrated that UNHS has significantly reduced the time to referral and surgery for cochlear implants in these children.

AIMS

This study aims to evaluate the relationship between earlier implantation and language development, the time taken to achieve age-appropriate language, and the effect of socioeconomic status on language skills.

METHODS

This is a retrospective cohort study comparing prelingual children with severe to profound bilateral hearing loss who underwent cochlear implantation in SCIP before and after the introduction of the UNHS. The language outcomes were assessed using the Preschool Language Scale and/or the Peabody Picture Vocabulary Test. For the purpose of our study, the standard scores of these tests were expressed as global language scores (GLS). GLSs between 85 and 115 are considered within normal range for age. The socioeconomic status was categorized based on the New Zealand Index of Deprivation (NZDep).

RESULTS

Children in the post-UNHS group (46/95 children) were referred to SCIP and received CI at a significantly earlier age (mean = 7 vs 20 mo, p = 8.95E-10, and mean = 13 vs. 24.7 mo, p = 1.43E-07). At 2 years postimplantation, the GLS was significantly higher in the post-UNHS group (mean scores = 93.3 vs. 79.1, p = 0.0213). The scores remained statistically higher in the post-UNHS group when assessed at 3 and 4 years postimplantation. At 2, 3, and 4 years postimplantation, there is a significant linear decrease in GLS with increasing age at cochlear implantation. We found no correlation between NZDep and GLS.

CONCLUSION

Children identified through UNHS have the advantage of earlier diagnosis, earlier hearing intervention, and longer duration with the implants, and they can achieve age-appropriate spoken language after 2 years of implantation.

[Hearing care network for early identification of delayed hearing loss in preschool children]

Objective:To establish a hearing care network for preschool children in Nanjing, to perform early identification and intervention for delayed hearing loss, and to evaluate the application effect of the hearing care network. Methods:Through the establishment of a hearing care network, hearing screening, diagnosis and follow-up of preschool children were conducted. Distortion product otoacoustic emissions（DPOAE） was adopted for primary hearing screening. Children who failed in the primary screening were re-screened within half a month. DPOAE and acoustic impedance test were used for hearing re-screening. Clinical diagnosis and audiological evaluation were performed for children who failed in the re-screening. Speech assessment, hearing aid intervention, and audio-speech follow-up were conducted for children diagnosed with delayed hearing loss. Results:Among 29 919 preschool children completing the hearing screening from May 2019 to September 2022, 3208 cases（10.7%） failed the primary screening and 1437 cases（47.7%） failed the re-screening. Total 747 children completed the hearing diagnosis, and 70 children were diagnosed with delayed hearing loss, with a detection rate of 0.23%. Among them, 20 cases were accompanied by language development delay, in which 12 cases received hearing aids and 2 cases received cochlear implantation. In addition, speech assessment and audiological follow-up were completed for 53 children. Conclusion:The hearing screening for preschool children is beneficial for early detection of children with delayed hearing loss and language development delay. Besides, the establishment of hearing care network is conducive to early identification and intervention of children with hearing loss.

Virtual Assessment of Deaf and Hard of Hearing Students in the Schools

The COVID-19 pandemic placed stress on all aspects of the educational system. Many state departments of education acknowledged the disruption to individualized education program evaluation and implementation but insisted that evaluation timelines and services continue undisrupted. School psychologists were therefore forced to navigate the viability of virtual assessment without established research supporting this type of student evaluation. Formal assessments used in the identification of learning disabilities and other areas of disability were not standardized with virtual administration procedures; however, many test publishers have offered guidelines for online administration. These guidelines may not be suitable for test administration with deaf and hard of hearing (DHH) children. Through the presentation of two case studies, this article explores some of the available administration guidelines and evaluates their appropriateness for use with DHH children. Information in this article informs current practice of school psychology in a virtual environment.

Being a Deaf Woman in Bedouin Society

Israel's Bedouin population, an ethnic minority, has a higher incidence of deafness than that reported in the literature, but is not studied sufficiently. A patriarchal and collective society, in recent years it has undergone accelerated change spurred by Israel's urbanization policy. Deaf women are an inseparable part of Bedouin society, but they are transparent and their needs are not met. In a qualitative study of 23 Bedouin women with congenital deafness who participated in the only social club for the deaf among the Bedouin population in southern Israel, these women were found to exist between dreams and frustration, between hope and despair, between strength and loneliness-induced weakness, and between transparency and visibility. Focusing on these aspects, the authors describe the experience of being a deaf woman in Bedouin society. Their findings are applicable to deaf women who are members of minorities worldwide.

Views of reproductive genetic carrier screening participants regarding screening for genes associated with non-syndromic hearing loss

OBJECTIVE

Reproductive genetic carrier screening (RGCS) panels often include genes associated with non-syndromic hearing loss (NSHL) despite a lack of evidence of acceptability. Although some couples take steps to avoid having a child who is deaf, there are effective interventions for children who are deaf. There is no consensus whether deafness is considered a disabling condition.

METHOD

This study explored views of people who had RGCS, without genes for NSHL, about this topic. Online surveys were sent to 2186 people who had a low chance RGCS result and 655 completed the survey (participation rate 30%).

RESULTS

Sixty-three percent (N = 412) think deafness is a serious health condition. The majority agreed (60%, N = 391) that with support (i.e. hearing aids/cochlear implants) deafness is a minor condition in children. Most (84%, N = 545) agreed genes for NSHL should be included in RGCS. Thirty-five percent (N = 231) indicated they would make different reproductive decisions if they had an increased chance of having a child born deaf; 31% would not change their reproductive plans and 34% were unsure what they would do.

CONCLUSION

While the majority support inclusion of genes associated with NSHL in RGCS, there was uncertainty about the severity of deafness as a health condition and there was no consensus on whether it is a health condition that warrants changing reproductive decisions.

[Molecular genetic diagnosis in children with cochlear implants in the Western french speaking part of Switzerland]

Hearing loss is the most frequent sensory deficit at birth. Newborn hearing screening helps with early identification and clinical management of hearing deficits. A cochlear implantation is advised for profound hearing loss. Previously, an etiologic diagnosis was difficult to obtain, and many laboratory tests were required. Today, genetics has up to 60% success rate in etiologic diagnosis and is now part of the international pediatric ENT recommendations. The Centre Universitaire Romand des Implants Cochléaires (CURIC) follows children with cochlear implants. From 2015 to 2021, 26 implanted children received testing, with a 73% success rate. The genetic diagnosis helped guide their clinical management and helped to avoid unnecessary and costly clinical testing.

Language outcomes after cochlear implant

QUESTION

A young infant seen in our practice was diagnosed with profound congenital hearing loss. Their parents want to pursue cochlear implant surgery for their child, but they are concerned about language acquisition before and after the surgery. What should they know about the procedure, and how can they improve language outcomes?

ANSWER

Congenital hearing loss is often identified on newborn screening hearing tests. Cochlear implants may lead to overall improved spoken language skills among children with profound hearing loss. Some factors associated with successful language acquisition in children after cochlear implant surgery include having the procedure at an earlier age and family engagement in early intervention programs. Learning sign language before cochlear implant surgery may improve subsequent language outcomes and support the child's cognitive and socioemotional success.

Hearing outcomes in preterm infants with confirmed hearing loss

OBJECTIVES

Premature infants are at high risk for hearing loss (HL). The aim of the present study is to assess the frequency of preterm infants affected by HL who experience hearing improvement over months and evaluate possible factors associated with hearing changes.

METHODS

This retrospective study was conducted in a third-level referral audiologic center. Preterm infants with a confirmed diagnosis of sensorineural HL within the first 3 months of life were reassessed at 18 months corrected age using the click-evoked auditory brainstem response between January 1, 2012, and June 30, 2020. The frequency of hearing improvement and associations between possible risk factors and hearing changes were evaluated.

RESULTS

A total of 138 preterm infants (71 male and 67 female; mean gestational age: 30⁺² weeks) were assessed. The percentages of hearing improvement and hearing threshold normalization were 58.7% (81/138) and 35.5% (49/138), respectively. We observed a higher frequency of hearing improvement among preterm infants who had received exclusive breastfeeding or mixed feeding compared with those who had received exclusive infant formula (80% versus 29.3%, P < 0.001).

CONCLUSION

This study confirms the importance of performing a long audiological follow-up and postponing the indication for cochlear implantation in children with a history of preterm birth. Because of the expression of mesenchymal stem cells and high total antioxidant capacity, breast milk might play a protective role in the auditory system of preterm infants. These findings could have important implications for clinical practice, positively impacting the long-term hearing outcomes of preterm infants.

Estimating Early Language Input in Deaf and Hard of Hearing Children With the Language Access Profile Tool

PURPOSE

The purpose of this study was to describe the Language Access Profile Tool (LAPT) and its psychometric properties with the aim of evaluating its suitability as an alternative to the deaf or hard of hearing (DHH) Language Exposure Assessment Tool (D-LEAT) in clinical practice with DHH children age 12 years and younger.

METHOD

We administered both the LAPT and D-LEAT to the caregivers of 105 DHH children 12 years old and younger from across the United States, 40% of whom were interviewed again after a delay of at least 1 month. Each interview resulted in a child-specific estimate of their cumulative experience with language input, expressed as a proportion divided across eight categories.

RESULTS

Participants in the sample reported experience with all eight input categories, but four categories were common and four were rare. Estimates for all input categories were consistent at both initial and follow-up interviews. Estimates for each input category were also strongly correlated with the corresponding estimates from the D-LEAT, although correlations for the rare categories should be interpreted cautiously.

CONCLUSIONS

The LAPT demonstrates sufficient test-retest reliability and convergent validity to be a useful and more user-friendly alternative to the D-LEAT. We provide recommendations for how the LAPT and the D-LEAT can be best used in their current form.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.20669001.

Clinical evaluation and etiologic diagnosis of hearing loss: A clinical practice resource of the American College of Medical Genetics and Genomics (ACMG)

Hearing loss is a common and complex condition that can occur at any age, can be inherited or acquired, and is associated with a remarkably wide array of etiologies. The diverse causes of hearing loss, combined with the highly variable and often overlapping presentations of different forms of hearing loss, challenge the ability of traditional clinical evaluations to arrive at an etiologic diagnosis for many deaf and hard-of-hearing individuals. However, identifying the etiology of hearing loss may affect clinical management, improve prognostic accuracy, and refine genetic counseling and assessment of the likelihood of recurrence for relatives of deaf and hard-of-hearing individuals. Linguistic and cultural identities associated with being deaf or hard-of-hearing can complicate access to and the effectiveness of clinical care. These concerns can be minimized when genetic and other health care services are provided in a linguistically and culturally sensitive manner. This clinical practice resource offers information about the frequency, causes, and presentations of hearing loss and suggests approaches to the clinical and genetic evaluation of deaf and hard-of-hearing individuals aimed at identifying an etiologic diagnosis and providing informative and effective patient education and genetic counseling.

Follow-up on children with suspected bilateral congenital hearing loss identified through universal newborn hearing screening program in Taiwan: A national-based population study

OBJECTIVE

This investigation was to ascertain the performance of the UNHS in Taiwan.

METHODS

The predefined questionnaire was delivered on the phone in 2016. The descriptive analysis was applied to the research data. 941 neonates in birth cohorts 2013-2014 who were documented as a bilateral referral in the national UNHS tracking system were targeted. The respondents were either caregivers or family members.

RESULTS

40.3% of 941 children were lost to follow-up, and 66.24% of 363 children were diagnosed with SNHL. 45.15% of 163 children used hearing amplification device(s). 77.46% of hearing amplification device users and 7.51% of non-users participated in the auditory training courses. By six months of age, 38.51% and 22.58% of children diagnosed with bilateral SNHL commenced the hearing amplification device fitting and the auditory training courses, respectively.

CONCLUSIONS

More efforts are needed to enhance the performance of the UNHS to achieve national goals stated in the 2014 Taiwan UNHS Revised Guidelines and the well-known benchmarks set by the JCIH in 2007. The development of an electronic tracking system for storing and sharing information on the follow-up on children with congenital hearing loss was as significant as the improvements in the understanding of early hearing detection and intervention of the public and stakeholders.

Characterizing North Carolina's Deaf and Hard of Hearing Infants and Toddlers: Predictors of Vocabulary, Diagnosis, and Intervention

PURPOSE

This study sought to (a) characterize the demographic, audiological, and intervention variability in a population of Deaf and Hard of Hearing (DHH) children receiving state services for hearing loss; (b) identify predictors of vocabulary delays; and (c) evaluate factors influencing the success and timing of early identification and intervention efforts at a state level.

METHOD

One hundred DHH infants and toddlers (aged 4-36 months) enrolled in early intervention completed the MacArthur-Bates Communicative Development Inventories, and detailed information about their audiological and clinical history was collected. We examined the influence of demographic, clinical, and audiological factors on vocabulary outcomes and early intervention efforts.

RESULTS

We found that this sample showed spoken language vocabulary delays (production) relative to hearing peers and showed room for improvement in rates of early diagnosis and intervention. These delays in vocabulary and early support services were predicted by an overlapping subset of hearing-, health-, and home-related variables.

CONCLUSIONS

In a diverse sample of DHH children receiving early intervention, we identify variables that predict delays in vocabulary and early support services, which reflected both dimensions that are immutable, and those that clinicians and caretakers can potentially alter. We provide a discussion on the implications for clinical practice.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.19449839.

A fully integrated SNP genotyping system for hereditary hearing-loss detection

Hereditary hearing loss is one of the most common human neurosensory disorders, and there is a great need for early intervention methods such as genetically screening newborns. Single nucleotide polymorphisms (SNPs) are the major genetic targets for hearing-loss screening. In this study, a fully integrated SNP genotyping system was constructed to identify hereditary hearing loss-related genetic markers from human whole blood. The entire detection process, including blood cell lysis, nucleic acid extraction, the reaction mixture distribution, the chambers sealing and the two-colour multiplex competitive allele-specific polymerase chain reaction (KASP), can be automatically conducted in a self-contained cassette within 3 hours. To critically evaluate the performance of the system, its specificity, sensitivity and stability were assessed. Then, 13 clinical samples were genotyped with this fluidic cassette system to detect seven hotspot deafness-associated mutations in three genes (MT-RNR1, GJB2 and SLC26A4). The detection results of the cassette system were 100% concordant with those obtained by Sanger sequencing, proving its accuracy in the genetic screening of inherited hearing loss.

An Initial Investigation of the American Sign Language Version of the Self-Determination Inventory

Self-determination is a potential predictor of in-school and postschool success, yet it has not previously been examined in youth and young adults who are deaf or hard of hearing (DHH). The present study used a cross-sectional survey design to examine the reliability and validity of the American Sign Language (ASL) version of the Self-Determination Inventory: Student Report (ASL SDI:SR) and to develop an understanding of mean self-determination strengths and areas of need in a sample of youth and young adults who were DHH; 221 participants completed the ASL SDI:SR, including individuals representing each type of educational setting and each type of communication mode. The component with the highest mean score was psychological empowerment; the lowest mean score was for self-realization. The findings showed that the ASL SDI:SR produced reliable scores. Implications for future practice and research are discussed.

[The cochlear implantation in patients with syndromic deafness. Clinical examples]

OBJECTIVE

To describe clinical observations of patients with syndromic deafness.

RESULTS

Deaf patients with CHARGE, Crouzon, and Wildervanck syndromes were monitored at the Russian Research Clinical Center for Audiology and Hearing Rehabilitation (Moscow) in different years. All of them were diagnosed having bilateral congenital deafness. After collecting anamnesis, evaluating the results of computed tomography of the temporal bones, and audiological examination, it was decided to conduct the cochlear implantation.

CONCLUSION

The only method that allows patients with bilateral congenital deafness to gain hearing is the cochlear implantation. The malformations of the tympanic cavity structures, an abnormal course of the facial nerve canal lead to technical difficulties during the surgical stage of cochlear implantation. The navigation equipment, monitoring of the facial nerve makes it easier to find anatomical structures, as well as to avoid injuries.

Mitochondrial Strokes: Diagnostic Challenges and Chameleons

Mitochondrial stroke-like episodes (SLEs) are a hallmark of mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS). They should be suspected in anyone with an acute/subacute onset of focal neurological symptoms at any age and are usually driven by seizures. Suggestive features of an underlying mitochondrial pathology include evolving MRI lesions, often originating within the posterior brain regions, the presence of multisystemic involvement, including diabetes, deafness, or cardiomyopathy, and a positive family history. The diagnosis of MELAS has important implications for those affected and their relatives, given it enables early initiation of appropriate treatment and genetic counselling. However, the diagnosis is frequently challenging, particularly during the acute phase of an event. We describe four cases of mitochondrial strokes to highlight the considerable overlap that exists with other neurological disorders, including viral and autoimmune encephalitis, ischemic stroke, and central nervous system (CNS) vasculitis, and discuss the clinical, laboratory, and imaging features that can help distinguish MELAS from these differential diagnoses.

An Integrative Review of Current Practice Models and/or Process of Family-Centered Early Intervention for Children Who Are Deaf or Hard of Hearing

Over the past few decades, there has been an increasing shift toward emphasizing the importance of the child's family taking an active role in the habilitation process through family-centered early intervention (FCEI) programs. Accordingly, the Health Professions Council of South Africa recommends that early intervention services following confirmation of hearing loss must be family-centered within a community-based model of service delivery that is culturally congruent. The aim of this study was to explore and document current evidence reflecting trends in FCEI for children who are deaf or hard of hearing (DHH) by identifying and describing current practice models and/or processes of FCEI for these children. This study describes our first steps in formulating a framework for FCEI for children who are DHH in South Africa. An integrative literature review was conducted. Sage, Science Direct, PubMed, and Google Scholar databases were searched for studies published in English between January 2009 and January 2019 reporting on FCEI programs for children who are DHH. Studies that focused on the following were excluded from the study: speech and language outcomes of children, youth, and adults who are DHH; education for children who are DHH; universal newborn hearing screening; professionals' roles in early hearing detection and intervention; diagnosis of hearing loss; and sign language. Kappa statistics were performed to determine agreement between reviewers. Twenty-two studies were included in the review. Cohen's kappa revealed a substantial agreement (κ = 0.8) between reviewers for data extraction and synthesis in terms of the articles that met the criteria for inclusion in the review. Findings were discussed under 5 themes: caregiver involvement; caregiver coaching/information sharing; caregiver satisfaction; challenges with FCEI; and telehealth. Generally, there is sufficient evidence for FCEI, with caregivers indicating the need for full involvement in their children's care. Methods of caregiver involvement involving caregiver coaching/information sharing need to be culturally and linguistically appropriate, with sensitivities around time and manner. This increases caregiver satisfaction with intervention programs and improves outcomes for children who are DHH. Challenges identified by the studies raise implications for early hearing detection and intervention programs, as well as Departments of Health and Social Welfare. These included logistical challenges, professional-related challenges, and caregiver-related challenges. Various aspects of FCEI have been reported in the review. Findings of these studies have significant implications for the formulation of quality FCEI programs to ensure contextually relevant and contextually responsive care of children who are DHH.

Reducing interaural tonotopic mismatch preserves binaural unmasking in cochlear implant simulations of single-sided deafness

Binaural unmasking, a key feature of normal binaural hearing, can refer to the improved intelligibility of masked speech by adding masking that facilitates perceived separation of target and masker. A question relevant for cochlear implant users with single-sided deafness (SSD-CI) is whether binaural unmasking can still be achieved if the additional masking is spectrally degraded and shifted. CIs restore some aspects of binaural hearing to these listeners, although binaural unmasking remains limited. Notably, these listeners may experience a mismatch between the frequency information perceived through the CI and that perceived by their normal hearing ear. Employing acoustic simulations of SSD-CI with normal hearing listeners, the present study confirms a previous simulation study that binaural unmasking is severely limited when interaural frequency mismatch between the input frequency range and simulated place of stimulation exceeds 1-2 mm. The present study also shows that binaural unmasking is largely retained when the input frequency range is adjusted to match simulated place of stimulation, even at the expense of removing low-frequency information. This result bears implications for the mechanisms driving the type of binaural unmasking of the present study and for mapping the frequency range of the CI speech processor in SSD-CI users.

Benefits of Exome Sequencing in Children with Suspected Isolated Hearing Loss

Purpose: Hearing loss is characterized by an extensive genetic heterogeneity and remains a common disorder in children. Molecular diagnosis is of particular benefit in children, and permits the early identification of clinically-unrecognized hearing loss syndromes, which permits effective clinical management and follow-up, including genetic counselling. Methods: We performed whole-exome sequencing with the analysis of a panel of 189 genes associated with hearing loss in a prospective cohort of 61 children and 9 adults presenting mainly with isolated hearing loss. Results: The overall diagnostic rate using exome sequencing was 47.2% (52.5% in children; 22% in adults). In children with confirmed molecular results, 17/32 (53.2%) showed autosomal recessive inheritance patterns, 14/32 (43.75%) showed an autosomal dominant condition, and one case had X-linked hearing loss. In adults, the two patients showed an autosomal dominant inheritance pattern. Among the 32 children, 17 (53.1%) had nonsyndromic hearing loss and 15 (46.7%) had syndromic hearing loss. One adult was diagnosed with syndromic hearing loss and one with nonsyndromic hearing loss. The most common causative genes were STRC (5 cases), GJB2 (3 cases), COL11A1 (3 cases), and ACTG1 (3 cases). Conclusions: Exome sequencing has a high diagnostic yield in children with hearing loss and can reveal a syndromic hearing loss form before other organs/systems become involved, allowing the surveillance of unrecognized present and/or future complications associated with these syndromes.

Patient Report of Hearing in Neurofibromatosis Type 2: Recommendations for Clinical Trials

OBJECTIVE

To systematically evaluate published patient-reported outcome measures for the assessment of hearing function and hearing-related quality of life (QoL) and recommend measures selected by the Response Evaluation in Neurofibromatosis and Schwannomatosis International Collaboration (REiNS) as endpoints for clinical trials in neurofibromatosis type 2 (NF2).

METHODS

The REiNS Patient-Reported Outcomes Working Group systematically evaluated published patient-reported outcome measures of (1) hearing function and (2) hearing-related QoL for individuals with hearing loss of various etiologies using previously published REiNS rating procedures. Ten measures of hearing functioning and 11 measures of hearing-related QoL were reviewed. Measures were numerically scored and compared primarily on their participant characteristics (including participant age range and availability of normative data), item content, psychometric properties, and feasibility for use in clinical trials.

RESULTS

The Self-Assessment of Communication and the Self-Assessment of Communication-Adolescent were identified as most useful for adult and pediatric populations with NF2, respectively, for the measurement of both hearing function and hearing-related QoL. Measures were selected for their strengths in participant characteristics, item content, psychometric properties, and feasibility for use in clinical trials.

CONCLUSIONS

REiNS recommends the Self-Assessment of Communication adult and adolescent forms for the assessment of patient-reported hearing function and hearing-related QoL for NF2 clinical trials. Further work is needed to demonstrate the utility of these measures in evaluating pharmacologic or behavioral interventions.

The Value of Speech-Language Pathologists in Auditory Rehabilitation for Adults With Cochlear Implants

Background Standards for auditory rehabilitation are currently lacking for adults who receive cochlear implants. Speech recognition outcomes are highly variable, and many adults with cochlear implants present with suboptimal performance. Functional real-life communication abilities are not routinely measured clinically and are not strongly linked to performance on traditional measures of speech recognition. In fact, even individuals with relatively good speech recognition outcomes often present with persistent communication difficulties. In contrast to pediatric cochlear implant users, speech-language pathologists are not routinely involved in the rehabilitation of adults who receive cochlear implants. Purpose The purpose of this article is to describe the value of including a speech-language pathologist in a comprehensive approach to auditory rehabilitation for adults with cochlear implants. Method The theoretical and clinical foundations of incorporating a speech-language pathologist into an adult auditory rehabilitation program are discussed. A description of the skills and potential roles of the speech-language pathologist for providing adult cochlear implant rehabilitation services is presented, along with potential barriers to implementation. Conclusion Person-centered management of postlingually deafened adults with cochlear implants can be augmented by a more complete approach utilizing the skill set of a speech-language pathologist. Supplemental Material https://doi.org/10.23641/asha.14669652.

Effects of age-related hearing loss and hearing aid experience on sentence processing

Age-related hearing loss typically affects the hearing of high frequencies in older adults. Such hearing loss influences the processing of spoken language, including higher-level processing such as that of complex sentences. Hearing aids may alleviate some of the speech processing disadvantages associated with hearing loss. However, little is known about the relation between hearing loss, hearing aid use, and their effects on higher-level language processes. This neuroimaging (fMRI) study examined these factors by measuring the comprehension and neural processing of simple and complex spoken sentences in hard-of-hearing older adults (n = 39). Neither hearing loss severity nor hearing aid experience influenced sentence comprehension at the behavioral level. In contrast, hearing loss severity was associated with increased activity in left superior frontal areas and the left anterior insula, but only when processing specific complex sentences (i.e. object-before-subject) compared to simple sentences. Longer hearing aid experience in a sub-set of participants (n = 19) was associated with recruitment of several areas outside of the core speech processing network in the right hemisphere, including the cerebellum, the precentral gyrus, and the cingulate cortex, but only when processing complex sentences. Overall, these results indicate that brain activation for language processing is affected by hearing loss as well as subsequent hearing aid use. Crucially, they show that these effects become apparent through investigation of complex but not simple sentences.

A single-arm, open-label, intervention study to investigate the improvement of glucose tolerance after administration of the 5-aminolevulinic acid (5-ALA) in the patients with mitochondrial diabetes mellitus

BACKGROUND

Mitochondrial diabetes mellitus (MDM) is characterized by maternal inheritance, progressive neurosensory deafness, insulin secretory disorder, and progressive microvascular complications. Mitochondria are critical organelles that provide energy in the form of adenosine triphosphate (ATP). An impairment of ATP production in pancreatic β cells is regarded as the main cause of the insulin secretory disorder in patients with MDM, and these patients require insulin replacement therapy early after the diagnosis. The amino acid 5-aminolevulinic acid (5-ALA), a precursor of heme metabolites, is a non-proteinogenic δ amino acid synthesized in mitochondria. An addition of ferrous iron to 5-ALA enhances heme biosynthesis and increases ATP production through an upregulation of the respiratory complex. Several studies have reported that the administration of 5-ALA and ferrous iron to existing treatment improved the glycemic control in both patients with prediabetes and those with type 2 diabetes mellitus. The additional administration of 5-ALA and ferrous iron to MDM patients on insulin therapy may improve their insulin secretory capacity and glycemic control by improving their mitochondrial function. The findings of this study are expected to provide new treatment options for MDM and improve the patients' glycemic control and prognosis.

METHODS/DESIGN

This study is a single-arm, open-label pilot intervention study using clinical endpoints to investigate the effects of treatment with 5-ALA plus sodium ferrous citrate (SFC) to patients with MDM on their glucose tolerance. A total of 5 patients with MDM will be administered 5-ALA/SFC (200 mg/d) for 24 weeks. We will perform a 75-g oral glucose tolerance test before and at 24 weeks after the start of this 5-ALA/SFC treatment to evaluate glucose-dependent insulin responses.

DISCUSSION

To the best of our knowledge, this study will be the first assessment of the effects of 5-ALA/SFC in patients with MDM. This study will obtain an evidence regarding the effectiveness and safety of 5-ALA/SFC for patients with MDM.

TRIAL REGISTRATION

This study was registered with the University Hospital Medical Information Network (UMIN000040581) on July 1, 2020 and with the Japan Registry of Clinical Trials (jRCTs071200025) on August 3, 2020.

Melodic interval perception with acoustic and electric hearing in bimodal and single-sided deaf cochlear implant listeners

Two notes sounded sequentially elicit melodic intervals and contours that form the basis of melody. Many previous studies have characterized pitch perception in cochlear implant (CI) users to be poor which may be due to the limited spectro-temporal resolution and/or spectral warping with electric hearing compared to acoustic hearing (AH). Poor pitch perception in CIs has been shown to distort melodic interval perception. To characterize this interval distortion, we recruited CI users with either normal (single sided deafness, SSD) or limited (bimodal) AH in the non-implanted ear. The contralateral AH allowed for a stable reference with which to compare melodic interval perception in the CI ear, within the same listener. Melodic interval perception was compared across acoustic and electric hearing in 9 CI listeners (4 bimodal and 5 SSD). Participants were asked to rank the size of a probe interval presented to the CI ear to a reference interval presented to the contralateral AH ear using a method of constant stimuli. Ipsilateral interval ranking was also measured within the AH ear to ensure that listeners understood the task and that interval ranking was stable and accurate within AH. Stimuli were delivered to the AH ear via headphones and to the CI ear via direct audio input (DAI) to participants' clinical processors. During testing, a reference and probe interval was presented and participants indicated which was larger. Ten comparisons for each reference-probe combination were presented. Psychometric functions were fit to the data to determine the probe interval size that matched the reference interval. Across all AH reference intervals, the mean matched CI interval was 1.74 times larger than the AH reference. However, there was great inter-subject variability. For some participants, CI interval distortion varied across different reference AH intervals; for others, CI interval distortion was constant. Within the AH ear, ipsilateral interval ranking was accurate, ensuring that participants understood the task. No significant differences in the patterns of results were observed between bimodal and SSD CI users. The present data show that much larger intervals were needed with the CI to match contralateral AH reference intervals. As such, input melodic patterns are likely to be perceived as frequency compressed and/or warped with electric hearing, with less variation among notes in the pattern. The high inter-subject variability in CI interval distortion suggests that CI signal processing should be optimized for individual CI users.

One mutation, three phenotypes: novel metabolic insights on MELAS, MIDD and myopathy caused by the m.3243A > G mutation

INTRODUCTION

The m.3243A > G mitochondrial DNA mutation is one of the most common mitochondrial disease-causing mutations, with a carrier rate as high as 1:400. This point mutation affects the MT-TL1 gene, ultimately affecting the oxidative phosphorylation system and the cell's energy production. Strikingly, the m.3243A > G mutation is associated with different phenotypes, including mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS), maternally inherited diabetes and deafness (MIDD) and myopathy.

OBJECTIVES

We investigated urine metabolomes of MELAS, MIDD and myopathy patients in order to identify affected metabolic pathways and possible treatment options.

METHODS

A multiplatform metabolomics approach was used to comprehensively analyze the metabolome and compare metabolic profiles of different phenotypes caused by the m.3243A > G mutation. Our analytical array consisted of NMR spectroscopy, LC-MS/MS and GC-TOF-MS.

RESULTS

The investigation revealed phenotypic specific metabolic perturbations, as well as metabolic similarities between the different phenotypes. We show that glucose metabolism is highly disturbed in the MIDD phenotype, but not in MELAS or myopathy, remodeled fatty acid oxidation is characteristic of the MELAS patients, while one-carbon metabolism is strongly modified in both MELAS and MIDD, but not in the myopathy group. Lastly we identified increased creatine in the urine of the myopathy patients, but not in MELAS or MIDD.

CONCLUSION

We conclude by giving novel insight on the phenotypes of the m.3243A > G mutation from a metabolomics point of view. Directives are also given for future investigations that could lead to better treatment options for patients suffering from this debilitating disease.

Novel pathogenic mutations and further evidence for clinical relevance of genes and variants causing hearing impairment in Tunisian population

Introduction

Hearing impairment (HI) is characterized by complex genetic heterogeneity. The evolution of next generation sequencing, including targeted enrichment panels, has revolutionized HI diagnosis.

Objectives

In this study, we investigated genetic causes in 22 individuals with non-GJB2 HI.

Methods

We customized a Haloplex^HS kit to include 30 genes known to be associated with autosomal recessive nonsyndromic HI (ARNSHI) and Usher syndrome in North Africa.

Results

In accordance with the ACMG/AMP guidelines, we report 11 pathogenic variants; as follows; five novel variants including three missense (ESRRB-Tyr295Cys, MYO15A-Phe2089Leu and MYO7A-Tyr560Cys) and two nonsense (USH1C-Gln122Ter and CIB2-Arg104Ter) mutations; two previously reported mutations (OTOF-Glu57Ter and PNPT1-Glu475Gly), but first time identified among Tunisian families; and four other identified mutations namely WHRN-Gly808AspfsX11, SLC22A4-Cys113Tyr and two MYO7A compound heterozygous splice site variants that were previously described in Tunisia. Pathogenic variants in WHRN and CIB2 genes, in patients with convincing phenotype ruling out retinitis pigmentosa, provide strong evidence supporting their association with ARNSHI. Moreover, we shed lights on the pathogenic implication of mutations in PNPT1 gene in auditory function providing new evidence for its association with ARNSHI. Lack of segregation of a previously identified causal mutation OTOA-Val603Phe further supports its classification as variant of unknown significance. Our study reports absence of otoacoustic emission in subjects using bilateral hearing aids for several years indicating the importance of screening genetic alteration in OTOF gene for proper management of those patients.

Conclusion

In conclusion, our findings do not only expand the spectrum of HI mutations in Tunisian patients, but also improve our knowledge about clinical relevance of HI causing genes and variants.

[Quality of life in the elderly with an acquired single-sided deafness.]

The study aimed to assess a negative impact of an acquired single-sided deafness on quality of life of the elderly. Prospective analysis of outpatient records was carried out to identify elderly patients with single-sided deafness using pure tone audiometry. The main inclusion criteria were age over 60, ≥90 dB threshold of an affected ear, ≤30 dB threshold of an intact ear, an acquired single-sided hearing loss with sudden onset and deafness duration less than 5 years. Taking inclusion criteria into account two groups were formed: the main group with single-sided deaf patients (n=25) and the control group of normal hearing patients (n=25). All participants were surveyed with PSQ, HHIE, THI questionnaires. There were revealed some changes in psychological status in the group of patients with single-sided deafness in comparison with the group of normal hearing participants. The scores of the questionnaires showed increased stress and anxiety levels and deterioration in quality of life. Patients with single-sided deafness complained about severe tinnitus in an affected ear, worse speech intelligibility in noisy environment and a constant need to adapt to the different acoustic situations that in turn badly affected psychoemotional homeostasis, intensifying stress severity, and quality of life.

Evolving Identities of Adolescents Who Are Deaf or Hard of Hearing: A Scoping Review

The authors employed a scoping review to examine peer-reviewed journal articles published 2002-2020 focusing on adolescents who are deaf or hard of hearing and their self-reported identities. d/Deaf identity theory was explored in light of recent advances in developed countries, e.g., universal newborn hearing screening, increased access to mainstream school placements, and rising rates of cochlear implantation. Key themes were explored, including deafness acculturation, competing and complementary identities, and flexibility and fluidity. The results demonstrated that the way adolescents perceive their identity is evolving, in what is often a flexible and fluid process dependent on the adolescents' context. Other identities, such as those relating to ethnicity and culture, were often seen as equal in importance to one's d/Deaf identity. These findings are contrasted with those of wider research on d/Deaf identity, and further research investigating adolescents' perceptions of themselves is recommended.

Cochlear Implantation in Infants: Why and How

In children with congenital deafness, cochlear implantation (CI) prior to 12 months of age offers the opportunity to foster more typical auditory development during late infancy and early childhood. Recent studies have found a positive association between early implantation and expressive and receptive language outcomes, with some children able to achieve normal language skills by the time of school entry. Universal newborn hearing screening improved early detection and diagnosis of congenital hearing loss, allowing for earlier intervention, including decision-making regarding cochlear implant (CI) candidacy. It can be more challenging to confirm CI candidacy in infants; therefore, a multidisciplinary approach, including objective audiometric testing, is recommended to not only confirm the diagnosis but also to counsel families regarding expectations and long-term management. Surgeons performing CI surgery in young children should consider both the anesthetic risks of surgery in infancy and the ways in which mastoid anatomy may differ between infants and older children or adults. Multiple studies have found CI surgery in infants can be performed safely and effectively. This article reviews current evidence regarding indications for implantation in children younger than 12 months of age and discusses perioperative considerations and surgical technique.

[Result of Sanger sequencing for newborn carriers of single heterozygous variants of GJB2 or SLC26A4 gene by genechip analysis]

OBJECTIVE

To detect additional variants for newborn carriers of single heterozygous variants of the GJB2 or SLC26A4 gene by genechip analysis in Changsha area, and explore the variation spectrum of deafness-related genes in this region.

METHODS

For 462 newborns carrying single heterozygous variants of the GJB2 or SLC26A4 gene, all exons of the genes were subjected to Sanger sequencing. The pathogenicity of the variants was analyzed by database and literature search.

RESULTS

For 305 newborns carrying a heterozygous GJB2 variant, 143 (46.49%) were found to carry additional variants, including 29 (9.51%) with c.109G>A likely pathogenic variant, and 1 (6.48%) with c.551G>A pathogenic variant. Among 153 newborns carrying single heterozygous variant of the SLC26A4 gene, 2 (1.31%) were found with a c.281C>T variant, and 1 (0.65%) with a c.1547_1548ins pathogenic variant. Among 4 newborns simultaneously carrying GJB2 and SLC26A4 variants, two were found to carry c.109G>A and c.844T>C variants (clinical significance unknown), respectively.

CONCLUSION

For newborns carrying single heterozygous variants of the GJB2 or SLC26A4 gene by genechip analysis, the detection rate for other variants is quite high. Sanger sequencing can significantly improve the detection rate of high-risk newborns and enrich the variant spectrum of deafness genes.

[Current status of newborn deafness gene screeningin parts of China]

Objective:To analyze the current status of newborn deafness gene screening from 2016 to 2017 in multiple regions of China, and to provide a reference for further promotion and application. Method:The "newborn deafness gene screening questionnaire" was sent to 41 institutions in eastern, central and western China after expert demonstration. The survey content included status of genetic screening, screening methods, the number of screenings, and the status of positive detections from January 1st, 2016 to December 31th, 2017. Each institution returned the questionnaire, the investigator conducted data verification and quality sampling. Finally, we performed analysis of screening methods and the positive detection rate of each gene on questionnaires with complete data. Result:Forty-one questionnaires were sent out and 41 were returned, the questionnaire return rate was 100%, in which 12 questionnaires were complete. Of the 41 institutions, 15 carried newborn deafness gene screening, with a rate of 36.59%（15/41）. The highest rate was in the east（72.22%, 13/18）, and the differences among the regions were statistically significant. As for the screening methods, among 12 questionnaires with complete data, 9 variants in 4 genes and 20 variants in 4 genes accounted for the highest proportion, both with the rate of 33.33%（4/12）, followed by 15 variants in 4 genes（25%, 3/12） and 5 variants in 3 genes（8.34%, 1/12）. A total of 340, 521 neonates were included in the study, and 17, 036 were positive for screening, with a positive rate of 5.00%. Among them, the single heterozygous mutation rate of GJB2 gene was 2.43%（8269/340, 521）, the biallele mutation rate was 0.02%（56/340, 521）,the single heterozygous mutation rate of SLC26A4 gene was 1.99%（6771/340, 521）, the biallele mutation rate was 0.01%（39/340, 521）,the single heterozygous mutation rate of GJB3 gene was 0.33%（1140/340, 521）, the mitochondrial 12SrRNA gene mutation rate was 0.22%（746/340, 521） and the double-gene heterozygous mutation rate was 0.004%（15/340, 521）. Conclusion:From 2016 to 2017, the newborn deafness gene screening is more extensive in the eastern region of China than in the central and western regions. In institutions that have carried out deafness gene screening, 9 variants in 4 genes and 20 variants in 4 genes are widely used; the GJB2 gene and SLC26A4 gene mutations are the most common. The results could provide references for areas where deafness gene screening is about to be performed.