Attitudes of deaf individuals towards genetic testing

Recent advances have made molecular genetic testing for several forms of deafness more widely available. Previous studies have examined the attitudes of the deaf towards genetic testing, including prenatal diagnosis. This study examines the attitudes of deaf college students towards universal newborn hearing screening, including molecular testing for specific forms of deafness, as well as the utilization of genetic test results for mate selection. We found that there may be differences in the attitudes of deaf individuals who associate closely with the deaf community (DC), and those who have equal involvement with both the deaf and hearing communities (EIC). The majority perceived newborn hearing screening for deafness to be helpful. However, more members of the EIC than the DC groups support newborn testing for genes for deafness. While there was reported interest in using genetic testing for partner selection, most participants reported they would not be interested in selecting a partner to have children with a specific hearing status. The results of this study point out important differences that genetic professionals should be aware of when counseling deaf individuals.     

A focus group study of consumer attitudes toward genetic testing and newborn screening for deafness.

PURPOSE: Progress in identifying genes for deafness together with implementation of universal audiologic screening of newborns has provided the opportunity for more widespread use of molecular tests to detect genetic forms of hearing loss. Efforts to assess consumer attitudes toward these advances have lagged behind. METHODS: Consumer focus groups were held to explore attitudes toward genetic advances and technologies for hearing loss, views about newborn hearing screening, and reactions to the idea of adding molecular screening for hearing loss at birth. Focus group discussions were recorded, transcribed and analyzed. RESULTS: Five focus groups with 44 participants including hearing parents of deaf children, deaf parents and young deaf adults were held. Focus group participants supported the use of genetic tests to identify the etiology of hearing loss but were concerned that genetic information might influence reproductive decisions. Molecular newborn screening was advocated by some; however, others expressed concern about its effectiveness. CONCLUSION: Documenting the attitudes of parents and other consumers toward genetic technologies establishes the framework for discussions on the appropriateness of molecular newborn screening for hearing loss and informs specialists about potential areas of public education necessary prior to the implementation of such screening.     

Evaluation of newborn screening bloodspot-based genetic testing as second tier screen for bedside newborn hearing screening

PurposeBedside newborn hearing screening is highly successful in identifying deaf or hard-of-hearing infants. However, newborn hearing screening protocols have high loss to follow-up rates. We propose that bloodspot-based genetic testing for GJB2 alleles can provide a means for rapid confirmation in a subset of infants who fail bedside newborn hearing screening.MethodsWe performed a case-control study comparing the prevalence of common GJB2 mutations from deidentified bloodspots designated as “refer” by newborn hearing screening and contemporaneously selected randomly chosen controls designated as “pass.” Between March 2006 and December 2007, 2354 spots were analyzed for common alleles, c.35delG, c.167delT, c.235delC, and p.V37I in GJB2 with a subset reanalyzed by conventional Sanger sequencing to search for additional alleles.ResultsThe prevalence of biallelic GJB2 mutations in bloodspots from infants who referred by newborn hearing screening is approximately 1 in 50 (23/1177). In contrast, one bloodspot from an infant who passed newborn hearing screening was identified to harbor biallelic GJB2 mutations.ConclusionsThese findings show that when a newborn refers by newborn hearing screening, there is a significant chance that GJB2-related hearing loss is present. Bloodspot-based genetic testing for common GJB2 alleles should be considered as second tier testing for bedside newborn hearing screening.     

听力筛查联合遗传性耳聋基因检测在新生儿筛查中的应用

目的 探讨听力筛查联合遗传性耳聋基因检测在新生儿筛查中的应用。方法 选取2018年12月~2019年7月我院接受产检的产妇509例,对所有产妇进行遗传性耳聋基因检测,并在产妇完成分娩后48 h对新生儿作常规听力筛查,确诊新生儿是否存在听力障碍。结果 509例产妇经遗传性耳聋基因检测显示阳性16例,阳性率3.14%;听力筛查不通过同时伴有耳聋基因突变新生儿共5例,听力学诊断结合随访确诊3例新生儿存在听力障碍,包含1例GJB2 299-300delAT突变,1例GJB2 235delC突变、1例SLC26A4 919-2A＞G突变。结论 在新生儿常规听力筛查的同时提供遗传性耳聋基因检测,能够有效弥补听力筛查的不足,可用作听力筛查工作的有效补充,有助于筛查出迟发型及潜在性耳聋患儿,提升听力障碍的检出率。     

33911例新生儿听力联合耳聋基因筛查及随访结果的分析

目的通过分析新生儿听力联合耳聋基因筛查的结果,以及对阳性病例的随访和管理,提高遗传性耳聋的检出率。方法收集33911例新生儿听力联合耳聋基因筛查的结果,应用Sanger测序对听力未通过或基因筛查提示阳性的患儿进行验证。结果听力初筛通过率为93.32%,复筛为87.01%。耳聋基因筛查阳性率为4.18%。GJB2、SLC26A4、GJB3和12SrRNA基因变异的检出率分别为1.98%、1.58%、0.37%和0.25%。共检出126例迟发性耳聋,84例药物性耳聋,4例GJB2纯合/复合杂合变异,5例SLC26A4纯合/复合杂合变异。联合筛查发现GJB2、SLC26A4、GJB3和12SrRNA单杂合变异者听力初筛和复筛未通过的比例分别为6.75%和2.61%、3.3%和1.2%、0.72%和0.14%、0.36%和0%。纯合/单基因复合杂合变异、单基因杂合变异、多基因复合杂合以及GJB3纯合变异组听力筛查未通过率明显高于阴性组,差异具有统计学意义。结论基因检测是对新生儿听力筛查很好的补充。对阳性患儿的追踪管理能够有效提高耳聋的诊断率,但基因筛查不能等同于诊断,应综合分析基因检测、听力筛查和影像学的结果,Sanger/二代测序可作为重要的补充检查手段。     

Nationwide population genetic screening improves outcomes of newborn screening for hearing loss in China

PurposeThe benefits of concurrent newborn hearing and genetic screening have not been statistically proven due to limited sample sizes and outcome data. To fill this gap, we analyzed outcomes of newborns with genetic screening results.MethodsNewborns in China were screened for 20 hearing-loss–related genetic variants from 2012 to 2017. Genetic results were categorized as positive, at-risk, inconclusive, or negative. Hearing screening results, risk factors, and up-to-date hearing status were followed up via phone interviews.ResultsFollowing up 12,778 of 1.2 million genetically screened newborns revealed a higher rate of hearing loss by three months oF.A.ge among referrals from the initial hearing screening (60% vs. 5.0%, P < 0.001) and a lower rate of lost-to-follow-up/documentation (5% vs. 22%, P < 0.001) in the positive group than in the inconclusive group. Importantly, genetic screening detected 13% more hearing-impaired infants than hearing screening alone and identified 2,638 (0.23% of total) newborns predisposed to preventable ototoxicity undetectable by hearing screening.ConclusionIncorporating genetic screening improves the effectiveness of newborn hearing screening programs by elucidating etiologies, discerning high-risk subgroups for vigilant management, identifying additional children who may benefit from early intervention, and informing at-risk newborns and their maternal relatives of increased susceptibility to ototoxicity.     

Early hearing detection and intervention programs: opportunities for genetic services

Congenital hearing loss is relatively frequent and has serious negative consequences if it is not diagnosed and treated during the first few months of life. Babies with hearing loss who are identified early and provided with appropriate intervention develop better language, cognitive, and social skills. As a result of improvements in screening equipment and procedures, newborn hearing screening programs have expanded rapidly in recent years, and almost 90% of all newborns are now screened for hearing loss before leaving the hospital. Because 50% or more of congenital hearing loss is due to genetic causes, providers of genetic services should play an increasingly important role in newborn hearing screening, diagnostic, and intervention services. For this to happen, parents, public health officials, and primary health care providers need to become better informed about the benefits of genetic services for children with hearing loss and their families. Providers of genetic services also need to become better informed about the current status of Early Hearing Detection and Intervention (EHDI) programs and how they can contribute to continued improvement of these programs.     

Newborn genetic screening for hearing impairment: a population-based longitudinal study

PurposeThe feasibility of genetic screening for deafness-causing mutations in newborns has been reported in several studies. The aim of this study was to investigate the long-term results in those who screened positive for deafness mutations; these results are crucial to determine the cost-effectiveness to justify population-wide genetic screening.MethodsWe performed simultaneous hearing screening and genetic screening targeting four common deafness mutations (p.V37I and c.235delC of GJB2, c.919-2A>G of SLC26A4, and the mitochondrial m.1555A>G) in 5173 newborns at a tertiary hospital between 2009 and 2015. Serial audiometric results up to 6 years old were then analyzed in children with conclusive genotypes.ResultsNewborn genetic screening identified 82 (1.6%) babies with conclusive genotypes, comprising 62 (1.2%) with GJB2 p.V37I/p.V37I, 16 (0.3%) with GJB2 p.V37I/c.235delC, and 4 (0.1%) with m.1555A>G. Of these, 46 (56.1%) passed hearing screening at birth. Long-term follow-up demonstrated progressive hearing loss in children with the GJB2 p.V37I/p.V37I and p.V37I/c.235delC genotypes; this hearing loss deteriorated by approximately 1 decibel hearing level (dBHL) per year.ConclusionsWe delineated the longitudinal auditory features of the highly prevalent GJB2 p.V37I mutation on a general population basis and confirmed the utility of newborn genetic screening in identifying infants with late-onset or progressive hearing impairment undetectable by newborn hearing screening.     

Frequency of Usher syndrome in two pediatric populations: Implications for genetic screening of deaf and hard of hearing children

PurposeUsher syndrome is a major cause of genetic deafness and blindness. The hearing loss is usually congenital and the retinitis pigmentosa is progressive and first noticed in early childhood to the middle teenage years. Its frequency may be underestimated. Newly developed molecular technologies can detect the underlying gene mutation of this disorder early in life providing estimation of its prevalence in at risk pediatric populations and laying a foundation for its incorporation as an adjunct to newborn hearing screening programs.MethodsA total of 133 children from two deaf and hard of hearing pediatric populations were genotyped first for GJB2/6 and, if negative, then for Usher syndrome. Children were scored as positive if the test revealed ≥1 pathogenic mutations in any Usher gene.ResultsFifteen children carried pathogenic mutations in one of the Usher genes; the number of deaf and hard of hearing children carrying Usher syndrome mutations was 15/133 (11.3%). The population prevalence was estimated to be 1/6000.ConclusionUsher syndrome is more prevalent than has been reported before the genome project era. Early diagnosis of Usher syndrome has important positive implications for childhood safety, educational planning, genetic counseling, and treatment. The results demonstrate that DNA testing for Usher syndrome is feasible and may be a useful addition to newborn hearing screening programs.     

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.     

American College of Medical Genetics and Genomics guideline for the clinical evaluation and etiologic diagnosis of hearing loss

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 a 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 guideline offers information about the frequency, causes, and presentations of hearing loss and suggests approaches to the clinical evaluation of deaf and hard-of-hearing individuals aimed at identifying an etiologic diagnosis and providing informative and effective patient education and genetic counseling.Genet Med 2014:16(4):347–355.     

4023例新生儿耳聋基因线粒体12S rRNA突变的研究

目的本研究通过对新生儿耳聋基因线粒体12S rRNA突变的检测,为预防药物性耳聋的可行性提供支持。方法对4023例新生儿采用飞行时间质谱检测技术进行耳聋基因线粒体12S rRNA的检测,检测位点包括A1555G和C1494T。结果4023例新生儿耳聋基因检测结果中共发现5例12S rRNA A1555G纯合突变,突变比例为0．12％。结论耳聋基因线粒体12SrRNA的检测对预防药物性耳聋具有重大意义,倡导对新生儿进行耳聋基因线粒体12S rRNA筛查的理念。     

遗传性非综合征型耳聋的临床实践指南

遗传因素是非综合征型聋常见的致病原因。随着分子检测技术的发展和日臻成熟,基因诊断和遗传咨询越来越多地影响着耳聋的临床实践。新生儿听力筛查的普及有助于耳聋的早期发现,耳聋基因筛査和诊断的普及有助于明确其病因,临床基因诊断和遗传咨询则有助于耳聋的早期干预。至今发现的非综合征型聋的致病基因有110个,鉴定其致病基因在临床上仍存在很多挑战。临床遗传咨询和产前诊断的开展,对耳聋基因检测和数据解读提出了更高的要求。本指南阐述了非综合征型耳聋的人群发病率、致病基因谱、遗传方式、疾病发展过程、临床表现、基因型-表型对应关系、基因诊断、治疗和干预,以及耳聋预防和再发风险评估等关键问题,为遗传咨询师、临床耳科医师及基因检测专业人员提供指导。     

Implementing neonatal screening for congenital cytomegalovirus: addressing the deafness of policy makers

Congenital cytomegalovirus (CMV) infection is an important public health problem with approximately 7 in 1,000 newborns infected and consequently at risk for hearing impairment. Newborn hearing screening will fail to detect this hearing impairment in approximately half of the cases because late onset hearing loss is frequent. Hearing impairment has profound impact on cognitive and social development of children and their families, determining most of the disease burden of congenital CMV infection. The potential value of newborn screening for congenital CMV is increasingly discussed. To date, many experts acknowledge the benefit of antiviral treatment in the prevention of hearing deterioration in newborns with neurological symptoms, and the benefit of early identification of late-onset hearing impairment by means of extensive audiological follow up of infected infants. These opinions imply that the potential of newborn screening for CMV would lie in the identification of the large proportion of asymptomatic congenitally infected newborns at risk for developing late-onset hearing loss. Experience with postnatal antiviral treatment of symptomatic newborns is encouraging, but has not been studied in asymptomatic congenitally infected newborns. A large-scale study on the safety and effectiveness of combined screening and antiviral therapy for congenital CMV infection is the necessary next step to take and should not be delayed.     

Estimated number of loci for autosomal recessive severe nerve deafness within the Israeli Jewish population,with implications for genetic counseling

Deafness occurs in about 1 per thousand live births, and at least 50% of congenital deafness is hereditary. The aim of this study was to examine the number of loci for recessively in herited severe nerve deafness of early onset within the Israeli population and to compare the results to those obtained in other populations. The Jewish population in Israel originates from many countries and may be divided into Sephardi, Eastern and Ashkenazi Jews, and the matings will be intraethnic or interethnic. Data were obtained on 133 deaf couples who lived in the Tel Aviv area, through the files of the Helen Keller Center. Causes of deafness in the spouses were studied and data on their children were obtained. Among 111 couples who had recessive or possibly recessive deafness and had at least 1 child, there were 12 with only deaf children and 5 with both deaf and hearing children. The number of loci for recessive deafness in the whole group was estimated at 8–9. Intraethnic and interethnic matings gave an estimate of 6.7 and 22.0 loci, respectively, which indicates that within populations fewer loci exist with recessive mutations for deafness than between populations. it could be shown that the sharing of loci between spouses decreased with increasing geographical distance of their origin. The results provide data for genetic counseling in Israel for deaf couples who have no children or have one hearing or one deaf child.     

Factors influencing parental decision about genetics evaluation for their deaf or hard-of-hearing child

PurposeTo identify factors that are associated with why parents of deaf children who have had GJB2/GJB6 testing as part of a genetics research study do or do not take their children for genetics evaluation.MethodsSelf-administered questionnaire was completed by parents of a deaf child participating in a GJB2/GJB6 testing study.ResultsA total of 30 parents (representing 24 children) completed the questionnaire; 11 of 24 children (46%) underwent a genetics evaluation. Compared with parents who did not take their child for a genetics evaluation, those who did were more likely to (1) have supportive pediatricians, (2) feel it was important or would be helpful to their child, (3) recall the recommendation for evaluation, (4) have family members who wanted the child to have an evaluation, and (5) be Hispanic or Asian. Genetic test results, knowledge of genetics evaluation, psychosocial factors, language concerns, or structural factors were not substantively associated with attending a genetics evaluation.ConclusionParental perceptions, family environment, and pediatricians play a role in decisions regarding genetics evaluation. Because genetic testing for deafness likely will occur outside of traditional genetics clinics and without comprehensive genetics evaluation, efforts to increase pediatricians' awareness of the usefulness of genetics evaluation may be essential to ensure appropriate care for deaf and hard-of-hearing children as recommended by the American College of Medical Genetics.     

Estimated number of loci for autosomal recessive severe nerve deafness within the Israeli Jewish population, with implications for genetic counseling.

Deafness occurs in about 1 per thousand live births, and at least 50% of congenital deafness is hereditary. The aim of this study was to examine the number of loci for recessively inherited severe nerve deafness of early onset within the Israeli population and to compare the results to those obtained in other populations. The Jewish population in Israel originates from many countries and may be divided into Sephardi, Eastern and Ashkenazi Jews, and the matings will be intraethnic or interethnic. Data were obtained on 133 deaf couples who lived in the Tel Aviv area, through the files of the Helen Keller Center. Causes of deafness in the spouses were studied and data on their children were obtained. Among 111 couples who had recessive or possibly recessive deafness and had at least 1 child, there were 12 with only deaf children and 5 with both deaf and hearing children. The number of loci for recessive deafness in the whole group was estimated at 8-9. Intraethnic and interethnic matings gave an estimate of 6.7 and 22.0 loci, respectively, which indicates that within populations fewer loci exist with recessive mutations for deafness than between populations. It could be shown that the sharing of loci between spouses decreased with increasing geographical distance of their origin. The results provide data for genetic counseling in Israel for deaf couples who have no children or have one hearing or one deaf child.     

聋人婚前耳聋基因检测及婚配生育情况调查分析

目的了解婚前聋人基因检测及婚配生育情况,为预防耳聋提供依据。方法对自愿接受基因检测的情侣耳聋基因突变进行检测。结果聋人婚配模式是15对聋人与聋人婚配的9对占60％;聋人与健听人婚配占26．67％;聋人与重听人结婚的占13．33％。其中9对聋与聋在婚前进行遗传咨询占60．O％,接受致聋基因检测的仅有3对占20．0％。生育正常12例后代,1例听力正常的女孩为GJB2235delc杂合突变携带者,1例男婴,重度耳聋为SLC26A4IVS7—2A〉G杂合突变。结论婚前进行常见耳聋基因检测,是对耳聋预防与出生缺陷干预的有效措施。     

Performance of cochlear implant recipients with GJB2-related deafness

Congenital profound hearing loss affects 0.05-0.1% of children and has many causes, some of which are associated with cognitive delay. For prelingually-deafened cochlear implant recipients, the etiology of deafness is usually unknown. Mutations in GJB2 have been established as the most common cause of heritable deafness in the United States. In this report, we identify cochlear implant recipients with GJB2-related deafness and examine the performance of these individuals. Cochlear implant recipients received a battery of perceptive, cognitive, and reading tests. Neither subjects nor examiners knew the etiology of deafness in these individuals. The implant recipients were then examined for mutations in GJB2 using an allele-specific polymerase chain reaction assay, single-strand conformation polymorphism analysis, and direct sequencing. GJB2 mutations were the leading cause of congenital deafness among the cochlear implant recipients screened. Cochlear implant recipients with GJB2-related deafness read within one standard deviation of hearing controls better than other congenitally deaf cochlear implant recipients and non-cochlear implant recipients. Individuals with congenital deafness should be offered GJB2 screening. Positive results establish an etiologic diagnosis and provide prognostic, genetic, and therapeutic information. Effective rehabilitation for profoundly deaf individuals with GJB2-related deafness is possible through cochlear implantation.