A prospective, longitudinal study of the impact of GJB2/GJB6 genetic testing on the beliefs and attitudes of parents of deaf and hard-of-hearing infants

The views of people with a lived experience of deafness and the general public regarding genetic testing for deafness in the reproductive setting: A systematic review

PURPOSE

Genes associated with nonsyndromic hearing loss are commonly included in reproductive carrier screening panels, which are now routinely offered in preconception and prenatal care in many countries. However, there is debate whether hearing loss should be considered a medical condition appropriate for screening. This systematic review assessed research on opinions of those with a lived experience of deafness and the general public regarding genetic testing for deafness in the reproductive setting.

METHODS

Search of 5 online databases yielded 423 articles, 20 of which met inclusion criteria. We assessed the quality of each study, extracted data, and performed thematic analysis on qualitative studies.

RESULTS

Most studies indicated interest in the use of prenatal diagnosis for deafness. However, there were mixed views, and sometimes strongly held views, expressed regarding the reproductive options that should be available to those with an increased chance of having a child with deafness. Studies were small, from a limited number of countries, and most were too old to include views regarding preimplantation genetic testing.

CONCLUSION

There is a broad range of views regarding the use of reproductive options for deafness. Further research is essential to explore the benefits and harms of including nonsyndromic hearing loss genes in carrier screening.

Extended genetic diagnostics for children with profound sensorineural hearing loss by implementing massive parallel sequencing. Diagnostic outcome, family experience and clinical implementation

OBJECTIVES

The aim of this study was to investigate genetic outcomes, analyze the family experience, and describe the process of implementing genetic sequencing for children with profound sensorineural hearing loss (SNHL) at a tertial audiological center in southern Sweden.

DESIGN

This is a prospective pilot study including eleven children with profound bilateral SNHL who underwent cochlear implant surgery. Genetic diagnostic investigation was performed with whole exome sequencing (WES) complemented with XON-array to identify copy number variants, using a manually curated gene panel incorporating 179 genes associated with non-syndromic and syndromic SNHL. Mitochondrial DNA (mtDNA) from blood was examined separately. A patient reported experience measures (PREM) questionnaire was used to evaluate parental experience. We also describe here the process of implementing WES in an audiology department.

RESULTS

Six female and five male children (mean 3.4 years, SD 3.5 years), with profound bilateral SNHL were included. Genetic variants of interest were found in six subjects (55%), where three (27%) could be classified as pathogenic or likely pathogenic. Among the six cases, one child was found to have a homozygous pathogenic variant in MYO7A and two children had homozygous likely pathogenic variants in SLC26A4 and PCDH15, respectively. One was carrying a compound heterozygote frameshift variant of uncertain significance (VUS) on one allele and in trans, a likely pathogenic deletion on the other allele in PCDH15. Two subjects had homozygous VUS in PCDH15 and ADGRV1, respectively. In five of the cases the variants were in genes associated with Usher syndrome. For one of the likely pathogenic variants, the finding was related to Pendred syndrome. No mtDNA variants related to SNHL were found. The PREM questionnaire revealed that the families had difficulty in fully understanding the results of the genetic analysis. However, the parents of all eleven (100%) subjects still recommended that other families with children with SNHL should undergo genetic testing. Specifically addressed referrals for prompt complementary clinical examination and more individualized care were possible, based on the genetic results. Close clinical collaboration between different specialists, including physicians of audiology, audiologists, clinical geneticists, ophthalmologists, pediatricians, otoneurologists, physiotherapists and hearing habilitation teams was initiated during the implementation of the new regime. For all professionals involved, a better knowledge of the diversity of the genetic background of hearing loss was achieved.

CONCLUSIONS

Whole exome sequencing and XON-array using a panel of genes associated with SNHL had a high diagnostic yield, added value to the families, and provided guidance for further examinations and habilitation for the child. Great care should be taken to thoroughly inform parents about the genetic test result. Collaborations between departments were intensified and knowledge of hearing genomics was increased among the staff.

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.

Approach and solutions to congenital hearing impairment in Cameroon: perspective of hearing professionals

OBJECTIVES

To bring out the diagnostic attitude of hearing professionals in Cameroon towards congenital hearing impairment (CHI), assess availability of tests, neonatal screening, and create a national map of availability of treatment opportunities.

METHODS

We conducted a cross-sectional online-based survey from June to December 2021, concerning ear-nose-throat (ENT) specialists, hearing care professionals, speech therapists and ENT nurses. A Google Forms online questionnaire was used to collect data, filled by eligible professionals involved in hearing care in Cameroon.

RESULTS

A total of 93 professionals working in 31 different health facilities participated. A cumulative percentage of 79.9% of ENTs were found in just two out of 10 regions. Specialists sought by ENTs for assessment of patients with CHI included neurologists/neuro-pediatricians (96.8%), pediatricians (47.6%), other ENTs (34.9%), and psychologists (3.2%). Investigations requested included auditory-evoked brainstem response (ABR; 87.3%), otoacoustic emissions recording (OAE; 71.4%), and tympanometry (66.7%). There were eight OAE and nine ABR machines in the country. Twenty-five (88.6%) out of 31 facilities with otolaryngologists did not carry out systematic neonatal screening. Reasons included unavailability of equipment (21; 84%), and administrative delays (14; 56%). Sixteen (51.6%) facilities had ENTs with additional training in otologic surgery and 11 (35.5%) were equipped to perform ear surgery. Three centers (9.7%) specialized in hearing aid provision and maintenance services. Three hospitals (9.7%) had performed cochlear implantation.

CONCLUSION

Our results show scarcity and overt unevenness in distribution of specialists, equipment and solutions to CHI in Cameroon. A serious negative health care consequence of this shortage is the unavailability of universal newborn hearing screening and implementation programs.

Evaluating parental genetic knowledge of hearing loss with and without pre-test genetic counseling in a pediatric otolaryngology clinic

This study evaluated parental knowledge of genetics of sensorineural hearing loss (SNHL) and satisfaction following pre-test consult with and without genetic counseling (GC). A survey evaluating parents' knowledge of genetics for SNHL with and without GC was administered to parents of children with SNHL who were offered genetic testing. The survey also inquired about satisfaction, and decision to pursue genetic testing. Statistical tests included Fisher-Freeman-Halton test and Mann-Whitney test. Forty-nine participants completed the survey and were seen by both otolaryngology and GC intern (ENT + GC) (n = 24) or by otolaryngology (ENT) only (n = 25). Participation groups were not randomized. There were no significant differences in demographics between groups. Participants in the ENT + GC group had higher average genetics knowledge score of 72% correct (range 22%-100%), compared to the ENT only group with 44% (range 22%-78%) (p < .001). Participants in the ENT + GC group were more likely to know the different test result possibilities (p = .002), the most common form and pathogenic variant associated with SNHL (p < .001), that only a subset of genes are evaluated (p = .004), and that genetic testing may not explain SNHL etiology (p = .013), in comparison with the ENT only group. There was no significant difference in parental satisfaction or ultimate decision to undergo testing between groups. Obtaining genetic testing plays an integral role in the diagnosis and management of SNHL in the pediatric population. Our results suggest that the addition of GC increases parent knowledge of genetics and SNHL. This knowledge allows the family to make a more informed decision as to whether or not to pursue genetic testing.

Genetic and Non-genetic Workup for Pediatric Congenital Hearing Loss

Hearing loss is one of the most common concerns for presentation for a geneticist. Presentation prior to the age of one (congenital hearing loss), profound sensorineural hearing loss (SNHL), and bilateral hearing loss are sensitive and should raise concern for genetic causes of hearing loss and prompt referral for genetic testing. Genetic testing particularly in this instance offers the opportunity for anticipatory guidance including possible course of the hearing loss over time and also connection and evaluation for additional congenital anomalies that may be associated with an underlying syndrome vs. isolated genetic hearing loss.

Challenges to effective and autonomous genetic testing and counseling for ethno-cultural minorities: a qualitative study

Background

The Arab population in Israel is a minority ethnic group with its own distinct cultural subgroups. Minority populations are known to underutilize genetic tests and counseling services, thereby undermining the effectiveness of these services among such populations. However, the general and culture-specific reasons for this underutilization are not well defined. Moreover, Arab populations and their key cultural-religious subsets (Muslims, Christians, and Druze) do not reside exclusively in Israel, but are rather found as a minority group in many European and North American countries. Therefore, focusing on the Arab population in Israel allows for the examination of attitudes regarding genetic testing and counseling among this globally important ethnic minority population.

Methods

We used a qualitative research method, employing individual interviews with 18 women of childbearing age from three religious subgroups (i.e., Druze, Muslim, and Christian) who reside in the Acre district, along with focus group discussions with healthcare providers (HCPs; 9 nurses and 7 genetic counselors) working in the same geographical district.

Results

A general lack of knowledge regarding the goals and practice of genetic counseling resulting in negative preconceptions of genetic testing was identified amongst all counselees. Counselors’ objective of respecting patient autonomy in decision-making, together with counselees’ misunderstanding of genetic risk data, caused uncertainty, frustration, and distrust. In addition, certain interesting variations were found between the different religious subgroups regarding their attitudes to genetic counseling.

Conclusions

The study highlights the miscommunications between HCPs, particularly counselors from the majority ethno-cultural group, and counselees from a minority ethno-cultural group. The need for nuanced understanding of the complex perspectives of minority ethno-cultural groups is also emphasized. Such an understanding may enhance the effectiveness of genetic testing and counseling among the Arab minority group while also genuinely empowering the personal autonomy of counselees from this minority group in Israel and other countries.

A proposal for comprehensive newborn hearing screening to improve identification of deaf and hard-of-hearing children

Early intervention for newborns who are deaf or hard-of-hearing leads to improved language, communication, and social-emotional outcomes. Universal physiologic newborn hearing screening has been widely implemented across the United States with the goal of identifying newborns who are deaf or hard-of-hearing, thereby reducing time to diagnosis and intervention. The current physiologic newborn hearing screen is generally successful in accomplishing its goals but improvements could be made. In the past ten years, genetic testing has emerged as the most important etiological diagnostic test for evaluation of children with deafness and congenital cytomegalovirus has been recognized as a major cause of childhood deafness that may be treatable. A comprehensive newborn hearing screen that includes physiologic, genetic, and cytomegalovirus testing would have multiple benefits, including (1) identifying newborns with deafness missed by the current physiologic screen, (2) providing etiologic information, and (3) possibly decreasing the number of children lost to follow up. We present a framework for integrating limited genetic testing and cytomegalovirus screening into the current physiologic newborn hearing screening. We identify needed areas of research and include an overview of genome sequencing, which we believe will become available over the next decade as a complement to universal physiologic newborn hearing screening.

Genetic testing for congenital non-syndromic sensorineural hearing loss

INTRODUCTION

Approximately 60% of congenital pediatric hearing loss is of genetic etiology. To evaluate non-syndromic sensorineural hearing loss (NSSNHL), guidelines emphasize the use of comprehensive genetic testing (CGT) with next generation sequencing (NGS), yet these tests have limited accessibility, and potential CGT results may not be well understood. Thus, our objective was to analyze genetic testing practices and results for pediatric patients with NSSNHL.

METHODS

This was a retrospective chart review of pediatric patients (<18 years) diagnosed with NSSNHL from 2014 to 2017 at a tertiary pediatric hospital. Demographics, clinical data, CGT results, genetic testing practices and referral patterns were recorded and descriptively analyzed. Logistic regression models identified patient characteristics associated with pathogenic variants (PV) and variants of unknown significance (VOUS).

RESULTS

430 patients with congenital NSSNHL were included in the study. Genetic testing was ordered for 28% (n = 122) and resulted for 16% (n = 68). Most of the ordered tests (89%, n = 109) were the CGT panel. A majority (62%, n = 97) of the time in which genetic testing was not ordered, a referral for genetics consultation was placed. Amongst those with CGT results, a definitive genetic etiology was identified in 25% (n = 13), with less than half due to variants of GJB2/6. At least one PV was identified for 33% (n = 18), while at least one VOUS for 93% (n = 51). There were no significant differences in PV presence or number of VOUS across any characteristic except race. When compared to Caucasians, African Americans had significantly higher rates of VOUS with a rate ratio and 95% CI of 1.61 [1.11-2.34], p = 0.01, and Asians trended towards higher rates (1.96 [0.95-4.05], p = 0.06).

CONCLUSIONS

CGT is of high utility in the identification of relevant genetic variants and definitive genetic etiologies for pediatric patients with NSSNHL. Though guidelines recommend the early use of CGT, there are many barriers to appropriate testing and counseling, leading to low rates of CGT use at this single institution.

Reproductive guidance through prenatal diagnosis and genetic counseling for recessive hereditary hearing loss in high-risk families

OBJECTIVE

To evaluate the accuracy and validity of our protocol for prenatal diagnosis and genetic counseling in high-risk families at a clinic.

METHODS

Fifteen unrelated families with recessive nonsyndromic hearing loss (NSHL) in their family history and a positive attitude towards prenatal diagnosis were recruited in the present study. According to genetic information for each family, Sanger sequencing, fluorescence polymerase chain reaction (PCR)-based congenital deafness gene detection kit and multiple PCR-based target gene capture and high-throughput sequencing were used. Genetic counseling was offered to all participating families by genetic counselors and otologists. Prenatal diagnosis was provided to families with detected pathogenic mutations and who were expected to participate in subsequent prenatal diagnosis.

RESULTS

In this study, confirmed pathogenic mutations were detected in eight families, who were defined as high-risk families. These families all participated in prenatal diagnosis with positive attitudes. One novel variant (c.1687dupA) in the SLC264 gene was detected in a family. Through genetic counseling, the recurrence probability of NSHL in fetuses was 25% in six families, 0% in one family, and 50% in one family. The results of fetal DNA detection showed that one fetal variant was wild type, three were heterozygous mutations in SLC26A4, and one was a compound heterozygous mutation in SLC26A4. Two variants were heterozygous mutations in GJB2, and one was a homozygous mutation in GJB2. According to the test results for fetal DNA, prenatal diagnosis found that six fetuses had normal hearing, whereas two fetuses suffered from NSHL. After birth, six infants predicted to have normal hearing passed a newborn hearing screening test and two infants predicted to have NSHL were diagnosed with NSHL and received cochlear implants.

CONCLUSION

Our protocol for prenatal diagnosis and genetic counseling provides detailed information that can assist couples in high-risk families in preparing for infant arrival and future family planning. For the affected neonates, prenatal diagnosis and genetic counseling achieve an "early screening, early diagnosis, early intervention" strategy.

Diagnostic exome sequencing in children: A survey of parental understanding, experience and psychological impact

Clinical exome sequencing (CES) is increasingly being used as an effective diagnostic tool in the field of pediatric genetics. We sought to evaluate the parental experience, understanding and psychological impact of CES by conducting a survey study of English-speaking parents of children who had diagnostic CES. Parents of 192 unique patients participated. The parent's interpretation of the child's result agreed with the clinician's interpretation in 79% of cases, with more frequent discordance when the clinician's interpretation was uncertain. The majority (79%) reported no regret with the decision to have CES. Most (65%) reported complete satisfaction with the genetic counseling experience, and satisfaction was positively associated with years of genetic counselor (GC) experience. The psychological impact of CES was greatest for parents of children with positive results and for parents with anxiety or depression. The results of this study are important for helping clinicians to prepare families for the possible results and variable psychological impact of CES. The frequency of parental misinterpretation of test results indicates the need for additional clarity in the communication of results. Finally, while the majority of patients were satisfied with their genetic counseling, satisfaction was lower for new GCs, suggesting a need for targeted GC training for genomic testing.

Parents' attitudes toward genetic testing of children for health conditions: A systematic review

This review assessed parents' attitudes toward childhood genetic testing for health conditions, with a focus on perceived advantages and disadvantages. We also evaluated the factors that influence parents' attitudes toward childhood genetic testing. We searched Medline, Medline In-Process, EMBASE, PsycINFO, Social Work Abstracts and CINAHL. We screened 945 abstracts and identified 21 studies representing the views of 3934 parents. Parents reported largely positive attitudes toward childhood genetic testing across different genetic tests with varying medical utility. Parents perceived a range of advantages and disadvantages of childhood genetic testing. Childhood genetic testing was viewed by most as beneficial. Parents' education level, genetic status, sex and sociodemographic status were associated with reported attitudes. This yielded some conflicting findings, indicating the need for further research. Genetic counseling remains essential to support this population in making well-informed decisions. Targeted interventions tailored to specific families with different sociodemographic characteristics may be useful. Further research on the long-term impact of childhood genetic testing on families is warranted.

Opinions of hearing parents about the causes of hearing impairment of their children with biallelic GJB2 mutations

Hereditary hearing impairment (HI) caused by recessive GJB2 mutations is a frequent sensory disorder. The results of the molecular-based studies of HI are widely used in various genetic test systems. However, the ethical aspects are less described than the genetic aspects. The concerns expressed by individuals from groups with genetic risks must be included in the counseling of patients and their families. For evaluation of subjective opinions of hearing parents about the presumed causes of HI of their children, we analyze the cohort of parents having children with confirmed hereditary HI caused by biallelic recessive GJB2 mutations (in a homozygous or a compound heterozygous state). This study included 70 deaf children with HI due to mutations in the GJB2 gene and 91 questionnaires about the presumed causes of their deafness filled by their parents. Most of the parents at 78% (CI 68.4-85.4%) attributed their children's HI to "non-hereditary" causes and 22% (CI 14.7-31.6%) to "hereditary" causes (p < 0.05). Therefore, the prior opinions of the parents did not correspond to positive GJB2 genetic testing results. The subjective opinions of parents are probably partly based on family history, since respondents with deaf relatives in their pedigree more likely supposed hereditary causes for HI in their children than the respondents without deaf relatives (p < 0.001).

Aetiological diagnosis of child deafness: CODEPEH recommendations

Important progress in the fields of molecular genetics (principally) and diagnostic imaging, together with the lack of a consensus protocol for guiding the diagnostic process after confirming deafness by neonatal screening, have led to this new work document drafted by the Spanish Commission for the Early Detection of Child Deafness (Spanish acronym: CODEPEH). This 2015 Recommendations Document, which is based on the most recent scientific evidence, provides guidance to professionals to support them in making decisions regarding aetiological diagnosis. Such diagnosis should be performed without delay and without impeding early intervention. Early identification of the causes of deafness offers many advantages: it prevents unnecessary trouble for the families, reduces health system expenses caused by performing different tests, and provides prognostic information that may guide therapeutic actions.

Perception of Genetic Testing for Deafness and Factors Associated with Interest in Genetic Testing Among Deaf People in a Selected Population in Sub-Saharan Africa

Understanding the perceptions of genetic testing by members of the deaf community may help in planning deafness genetics research, especially so in the context of strong adherence to cultural values as found among native Africans. Among Yorubas in Nigeria, deafness is perceived to be caused by some offensive actions of the mother during pregnancy, spiritual attack, and childhood infections. We studied attitudes towards, and acceptance of genetic testing by the deaf community in Nigeria. Structured questionnaires were administered to individuals sampled from the Vocational Training Centre for the Deaf, the religious Community, and government schools, among others. The main survey items elicited information about the community in which the deaf people participate, their awareness of genetic testing, whether or not they view genetic testing as acceptable, and their understanding of the purpose of genetic testing. There were 150 deaf participants (61.3 % males, 38.7 % females) with mean age of 26.7 years ±9.8. A majority of survey respondents indicated they relate only with other members of the deaf community (78 %) and reported believing genetic testing does more good than harm (79.3 %); 57 % expressed interest in genetic testing. Interest in genetic testing for deafness or in genetic testing in pregnancy was not related to whether respondents relate primarily to the deaf or to the hearing community. However, a significantly higher number of male respondents and respondents with low education reported interest in genetic testing.

Impact of genetic counseling and Connexin-26 and Connexin-30 testing on deaf identity and comprehension of genetic test results in a sample of deaf adults: a prospective, longitudinal study

Using a prospective, longitudinal study design, this paper addresses the impact of genetic counseling and testing for deafness on deaf adults and the Deaf community. This study specifically evaluated the effect of genetic counseling and Connexin-26 and Connexin-30 genetic test results on participants' deaf identity and understanding of their genetic test results. Connexin-26 and Connexin-30 genetic testing was offered to participants in the context of linguistically and culturally appropriate genetic counseling. Questionnaire data collected from 209 deaf adults at four time points (baseline, immediately following pre-test genetic counseling, 1-month following genetic test result disclosure, and 6-months after result disclosure) were analyzed. Four deaf identity orientations (hearing, marginal, immersion, bicultural) were evaluated using subscales of the Deaf Identity Development Scale-Revised. We found evidence that participants understood their specific genetic test results following genetic counseling, but found no evidence of change in deaf identity based on genetic counseling or their genetic test results. This study demonstrated that culturally and linguistically appropriate genetic counseling can improve deaf clients' understanding of genetic test results, and the formation of deaf identity was not directly related to genetic counseling or Connexin-26 and Connexin-30 genetic test results.

Common genes for non-syndromic deafness are uncommon in sub-Saharan Africa: a report from Nigeria

INTRODUCTION

Little is known about the molecular epidemiology of deafness in sub-Saharan Africa (SSA). Even in Nigeria, the most populous African nation, no genetic studies of deafness have been conducted. This pioneering work aims at investigating the frequencies of gene mutations relatively common in other parts of the world (i.e. those in GJB2, GJB6, and mitochondrial DNA) among subjects from Nigeria with hearing loss (HL) with no evidence of acquired pathology or syndromic findings. In addition, we review the literature on the genetics of deafness in SSA.

METHOD

We evaluated 81 unrelated deaf probands from the Yoruba tribe residing in Ibadan, a suburban city in Nigeria, for the aetiology of their deafness. Subjects underwent genetic testing if their history was negative for an environmental cause and physical examination did not find evidence of a syndrome. Both exons of GJB2 and mitochondrial DNA flanking the 1555A>G mutations were PCR-amplified followed by Sanger sequencing. GJB6 deletions were screened via quantitative PCR.

RESULT

We identified 44 probands who had nonsyndromic deafness with no environmental cause. The age at study time ranged between 8 months and 45 years (mean=24 years) and age at onset was congenital or prelingual (<age 2 years) in 37 (84%) probands and postlingual in 7 (16%) probands. Among these, 35 probands were the only affected members of their families (simplex cases), while there were at least two affected family members in nine cases (multiplex). Molecular analyses did not show a pathogenic variant in any one of the 44 probands studied.

CONCLUSION

GJB2, GJB6 and mitochondrial DNA 1555A>G mutations were not found among this initial cohort of the deaf in Nigeria. This makes imperative the search for other genes in the aetiology of HL in this population.

Genetic counseling and prenatal diagnosis for hereditary hearing loss in high-risk families

OBJECTIVE

Genetic counseling and prenatal diagnosis are very necessary and accurate to detect hereditary hearing loss, especially in high-risk families. Prenatal diagnosis is testing for diseases or conditions in fetuses before born, which gives parents the chance to prepare psychologically, financially and medically for the probable health and educational needs of the affected neonates.

METHODS

54 unrelated families with children affected with non-syndromic sensorineural hearing loss were enrolled in the study and received genetic analysis with microarray and DNA sequencing technologies. Genetic counseling was provided to each participating families, and prenatal diagnosis was given to those at risk and would like to know their fetuses' genotypes and probable hearing statuses.

RESULTS

Half the cases in the present study were diagnosed with confirmed pathogenic mutations and clear inheritance patterns. After receiving genetic counseling, 24 carrier couples with pathogenic mutations chose to proceed prenatal diagnosis, the results of which were in accordance with the pregnancy outcomes. Infants prenatally detected to be monoallelic mutation carriers and those harbored neither deafness-causing mutations form their parents passed newborn hearing screening and six-month follow-ups, while neonates prenatally detected to be carriers of diallelic or compound heterozygous mutations developed hearing loss after birth.

CONCLUSIONS

With appropriate genetic counseling and support services provided, the genetic testing and the prenatal diagnosis of hearing loss were valued by carrier couples for the information provided for future family planning and probably the preparation for the health and educational needs of the affected neonates.

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.

Effect of pre-test genetic counseling for deaf adults on knowledge of genetic testing

Empirical data on genetic counseling outcomes in the deaf population are needed to better serve this population. This study was an examination of genetics knowledge before and after culturally and linguistically appropriate pre-test genetic counseling in a diverse deaf adult sample. Individuals ≥18 years old with early-onset sensorineural deafness were offered connexin-26/30 testing and genetic counseling. Participants completed questionnaires containing 10 genetics knowledge items at baseline and following pre-test genetic counseling. The effects of genetic counseling, prior beliefs about etiology, and participant’s preferred language on genetics knowledge scores were assessed (n = 244). Pre-test genetic counseling (p = .0007), language (p < .0001), prior beliefs (p < .0001), and the interaction between counseling and beliefs (p = .035) were predictors of genetics knowledge. American Sign Language (ASL)-users and participants with “non-genetic/unknown” prior beliefs had lower knowledge scores than English-users and participants with “genetic” prior beliefs, respectively. Genetics knowledge improved after genetic counseling regardless of participants’ language; knowledge change was greater for the “non-genetic/unknown” beliefs group than the “genetic” beliefs group. ASL-users’ lower knowledge scores are consistent with evidence that ethnic and cultural minority groups have less genetics knowledge, perhaps from exposure and access disparities. Culturally and linguistically appropriate pre-test genetic counseling significantly improved deaf individuals’ genetics knowledge. Assessing deaf individuals’ prior beliefs is important for enhancing genetics knowledge.

Parental attitudes toward genetic testing for prelingual deafness in China

OBJECTIVE

Recent advances in molecular biology of hearing and deafness have made genetic testing an option for deaf individuals and their families. In China, DNA microarray and other genetic testing method has been applied to rapid genetic diagnosis of non-syndromic hearing loss. However, there is no information about the interests in such testing in China. The purpose of this study is to document the attitudes of parents with normal hearing who have one or more deaf children toward diagnostic, carrier, and prenatal genetic testing for deafness.

METHODS

A structured, self-completion questionnaire was given to delegates at a conference held at Hubei Rehabilitation Research Center for Deaf Children, Wuhan, China on March 3, 2010. Of 366 surveys distributed, 290 were completed and returned.

RESULTS

Ninety-four percent of the respondents had a positive attitude toward genetic testing. Seventy-two percent stated that they were interested in genetic testing of deaf child. Of the individuals who were interested in such testing, 69% would consider having prenatal genetic testing for deafness.

CONCLUSION

The present study provided evidence of a predominantly positive attitude toward genetics. Appropriate genetic counseling can help parents to understand the risk, benefits, and limitations of genetic testing for prelingual deafness.