Etiology and audiological outcomes at 3 years for 364 children in Australia

Prevalence and Profiles of Late-Onset Hearing Loss in Preschool Children with Autism Spectrum Disorder Who Passed Newborn Hearing Screening in a South East Asian Population

Prevalence of hearing loss in children with autism spectrum disorder (ASD) is uncertain, as it is more challenging to assess hearing function in children with developmental difficulties (DD). We aimed to determine the prevalence and profiles of hearing loss in preschool children with ASD in a Southeast-Asian population who passed newborn hearing screening. A retrospective study of preschool children with DD (ASD, Global Developmental Delay (GDD), and Speech and Language Delay (SLD)) attending the Child Development Unit (CDU) at our hospital was performed. Three hundred and thirty-three children (ASD: n = 129; GDD: n = 110; and SLD: n = 94) underwent hearing assessments. Of these, 10.8% of children (n = 36, comprising 15 with ASD, 12 with GDD and 9 with SLD) had confirmed hearing loss. Hearing loss was predominantly bilateral in children with ASD and GDD; in those with SLD, unilateral and bilateral hearing loss were equally common. Conductive hearing loss occurred as frequently as sensorineural hearing loss in children with ASD and SLD, but was the dominant subtype in those with GDD. Moderate to severe hearing loss (n = 2) was noted only in children with ASD. Children with ASD and GDD required significantly more audiology visits and procedures to obtain conclusive hearing test results, compared to those with SLD. The need to identify hearing loss and monitor for resolution is particularly important in vulnerable populations with communication deficits, such as in those with ASD.

Language development in children from a public cochlear implant program

OBJECTIVE

To evaluate the rate of loss to follow-up in a cochlear implant program from the public health system in Southern Brazil as well as the characteristics of hearing loss, sociodemographic, sociocultural and the development of oral language in children with prelingual deafness.

METHODS

Retrospective cohort study with children who underwent CI surgery between 2010 and 2020. Data was collected through of interviews and review of medical records. The language development assessment was performed using the MUSS, MAIS and IT-MAIS scales. For the classification of language development, we used as parameters the values (mean ± SD) found in a previous national study. From those values, the Z-score for each patient at each hearing age (time of experience with the cochlear implant) was calculated.

RESULTS

Of the 225 children implanted between 2010-2020, 129 were included in this study. The rate of loss to follow-up in the program was 42.6%. The mean age at first surgery was 40.5 (±16.9) months, with 77.5% of patients having received a unilateral implant. Language results below the expected for hearing age (

CONCLUSIONS

Most patients had an elevated mean age at cochlear implantation and there was a high rate of loss to follow-up and low attendance to speech and programming sessions. An overall poor language performance was found for this pediatric cochlear implant program from the public health system in Southern Brazil.

LEVEL OF EVIDENCE

Level 3 (Non-randomized cohort study).

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Key Words

• Cochlear implant
• Language development disorders
• Prelingual deafness

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Affiliation(s)

Alice Lang Silva Universidade Federal do Rio Grande do Sul (UFRGS), Programa de Pós-Graduação em Saúde da Criança e do Adolescente, Porto Alegre, RS, Brazil.
Isadora Martins da Silva Stumpf Hospital de Clínicas de Porto Alegre (HCPA), Serviço de Otorrinolaringologia, Porto Alegre, RS, Brazil
Laura Prolla Lacroix Universidade Federal do Rio Grande do Sul (UFRGS), Faculdade de Medicina, Porto Alegre, RS, Brazil
Debora Milena Ferreira Alves Universidade Federal do Rio Grande do Sul (UFRGS), Faculdade de Medicina, Porto Alegre, RS, Brazil
Adriana Laybauer da Silveira Hospital de Clínicas de Porto Alegre (HCPA), Serviço de Fonoaudiologia, Porto Alegre, RS, Brazil
Sady Selaimen da Costa Universidade Federal do Rio Grande do Sul (UFRGS), Programa de Pós-Graduação em Saúde da Criança e do Adolescente, Porto Alegre, RS, Brazil; Hospital de Clínicas de Porto Alegre (HCPA), Serviço de Otorrinolaringologia, Porto Alegre, RS, Brazil
Letícia Petersen Schmidt Rosito Hospital de Clínicas de Porto Alegre (HCPA), Serviço de Otorrinolaringologia, Porto Alegre, RS, Brazil; Universidade Federal do Rio Grande do Sul (UFRGS), Faculdade de Medicina, Porto Alegre, RS, Brazil

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The congenital hearing phenotype in GJB2 in Queensland, Australia: V37I and mild hearing loss predominates

GJB2 was originally identified in severe, non-syndromic sensorineural hearing loss (SNHL), but was subsequently associated with mild and moderate SNHL. Given the increasing utilisation of genetic testing pre-conceptually, prenatally, and neonatally, it is crucial to understand genotype-phenotype correlations. This study evaluated the nature and frequency of GJB2 variants in an Australian paediatric population with varying degrees of SNHL ascertained through newborn hearing screening. Audiograms from individuals with GJB2 variants and/or a GJB6 deletion (GJB6-D13S11830) were retrospectively reviewed (n = 127). Two-thirds were biallelic (homozygous/compound heterozygous) for pathogenic/likely pathogenic variants of GJB2 and/or GJB6 (n = 80). The most frequent variant was c.109 G > A, followed by c.35delG and c.101 T > C. Compared to biallelic carriage of other GJB2 variants, c.109 G > A positive individuals (homozygous/compound heterozygous) were more likely to have mild HL at their initial and latest audiograms (p = 0.0004). Biallelic carriage of c.35delG was associated with moderately-severe or greater SNHL at both initial and latest audiograms (p = 0.007). The c.101 T > C variant presented with milder SNHL and U-shaped audiograms (p = 0.02). In this agnostically identified cohort, mild SNHL predominated in GJB2/GJB6 carriers in contrast to previous studies targeting individuals with significant loss. Consequently, c.109 G > A, associated with milder phenotypes, was the most frequent. This study provides valuable data to support prognostic confidence in genetic counselling.

Audiological characteristics of children with congenital unilateral hearing loss: insights into Age of reliable behavioural audiogram acquisition and change of hearing loss

Objectives

The aims of this study were to report the audiological characteristics of children with congenital unilateral hearing loss (UHL), examine the age at which the first reliable behavioural audiograms can be obtained, and investigate hearing changes from diagnosis at birth to the first reliable behavioural audiogram.

Method

This study included a sample of 91 children who were diagnosed with UHL via newborn hearing screening and had reliable behavioural audiograms before 7 years of age. Information about diagnosis, audiological characteristics and etiology were extracted from clinical reports. Regression analysis was used to explore the potential reasons influencing the age at which first reliable behavioural audiograms were obtained. Correlation and ANOVA analyses were conducted to examine changes in hearing at octave frequencies between 0.5 and 4 kHz. The proportions of hearing loss change, as well as the clinical characteristics of children with and without progressive hearing loss, were described according to two adopted definitions: Definition 1: criterion (1): a decrease in 10 dB or greater at two or more adjacent frequencies between 0.5 and 4 kHz, or criterion (2): a decrease in 15 dB or greater at one octave frequency in the same frequency range. Definition 2: a change of ≥20 dB in the average of pure-tone thresholds at 0.5, 1, and 2 kHz.

Results

The study revealed that 48 children (52.7% of the sample of 91 children) had their first reliable behavioural audiogram by 3 years of age. The mean age at the first reliable behavioural audiogram was 3.0 years (SD 1.4; IQR: 1.8, 4.1). We found a significant association between children's behaviour and the presence or absence of ongoing middle ear issues in relation to the delay in obtaining a reliable behavioural audiogram. When comparing the hearing thresholds at diagnosis with the first reliable behavioural audiogram across different frequencies, it was observed that the majority of children experienced deterioration rather than improvement in the initial impaired ear at each frequency. Notably, there were more instances of hearing changes (either deterioration or improvement), in the 500 Hz and 1,000 Hz frequency ranges compared to the 2,000 Hz and 4,000 Hz ranges. Seventy-eight percent (n = 71) of children had hearing deterioration between the diagnosis and the first behavioural audiogram at one or more frequencies between 0.5 and 4 kHz, with a high proportion of them (52 out of the 71, 73.2%) developing severe to profound hearing loss. When using the averaged three frequency thresholds (i.e., definition 2), only 26.4% of children (n = 24) in the sample were identified as having hearing deterioration. Applying definition 2 therefore underestimates the proportion of children that experienced hearing changes. The study also reported diverse characteristics of children with or without hearing deterioration.

Conclusion

The finding that 78% of children diagnosed with UHL at birth had a decrease in hearing loss between the hearing levels at first diagnosis and their first behavioural audiogram highlights the importance of monitoring hearing threshold levels after diagnosis, so that appropriate intervention can be implemented in a timely manner. For clinical management, deterioration of 15 dB at one or more frequencies that does not recover warrants action.

Insight into the Natural History of Pathogenic Variant c.919-2A>G in the SLC26A4 Gene Involved in Hearing Loss: The Evidence for Its Common Origin in Southern Siberia (Russia)

Pathogenic variants in the SLC26A4 gene leading to nonsyndromic recessive deafness (DFNB4), or Pendred syndrome, are some of the most common causes of hearing loss worldwide. Earlier, we found a high proportion of SLC26A4-related hearing loss with prevailing pathogenic variant c.919-2A>G (69.3% among all mutated SLC26A4 alleles that have been identified) in Tuvinian patients belonging to the indigenous Turkic-speaking Siberian people living in the Tyva Republic (Southern Siberia, Russia), which implies a founder effect in the accumulation of c.919-2A>G in Tuvinians. To evaluate a possible common origin of c.919-2A>G, we genotyped polymorphic STR and SNP markers, intragenic and flanking SLC26A4, in patients homozygous for c.919-2A>G and in healthy controls. The common STR and SNP haplotypes carrying c.919-2A>G were revealed, which convincingly indicates the origin of c.919-2A>G from a single ancestor, supporting a crucial role of the founder effect in the c.919-2A>G prevalence in Tuvinians. Comparison analysis with previously published data revealed the identity of the small SNP haplotype (~4.5 kb) in Tuvinian and Han Chinese carriers of c.919-2A>G, which suggests their common origin from founder chromosomes. We assume that c.919-2A>G could have originated in the geographically close territories of China or Tuva and subsequently spread to other regions of Asia. In addition, the time intervals of the c.919-2A>G occurrence in Tuvinians were roughly estimated.

The effect of SLC26A4 gene mutations on long-term rehabilitative outcomes in cochlear implant patients

BACKGROUND

SLC26A4 gene mutations related to hearing loss patients can obtain good hearing and speech rehabilitation effects after cochlear implantation (CI).

OBJECTIVE

To explore the long-term rehabilitative outcomes of CI in patients with different SLC26A4 mutation groups.

MATERIAL AND METHODS

Clinical data of 71 patients with SLC26A4 gene mutations who received CI in the Second Hospital of Lanzhou University from 2012 to 2015 were retrospectively reviewed. According to the genetic test results, use One-way ANOVA analysis to compare the differences in auditory results, categories of auditory performance (CAP) and speech intelligibility rating (SIR) index questionnaire scores and speech recognition rates among different groups in 4-5 years after CI.

RESULT

Compared with other genotypes of SLC26A4, the patients with homozygous mutation of c.919-2A > G in SLC26A4 had better hearing aid threshold at 500 Hz and better recognition rates of Yangyang words than other monoallelic mutation groups after CI (p < .05).

CONCLUSIONS AND SIGNIFICANCE

The most common hot spot mutation of SLC26A4 gene is c.919-2A > G. The patients with homozygous mutation of c.919-2A > G in SLC26A4 gene had partly better hearing and speech rehabilitation than other monoallelic mutation groups after CI.

Trajectory of hearing loss in children with unilateral hearing loss

Introduction

The aim of this study was to quantify the amount of deterioration in hearing and to document the trajectory of hearing loss in early identified children with unilateral hearing loss (UHL). We also examined whether clinical characteristics were associated with the likelihood of having progressive hearing loss.

Methods

As part of the Mild and Unilateral Hearing Loss Study, we followed a population-based cohort of 177 children diagnosed with UHL from 2003 to 2018. We applied linear mixed models to examine hearing trends over time including the average amount of change in hearing. Logistic regression models were used to examine the relationship between age and severity at diagnosis, etiology, and the likelihood of progressive loss and amount of deterioration in hearing.

Results

The median age of the children at diagnosis was 4.1 months (IQR 2.1, 53.9) and follow-up time was 58.9 months (35.6, 92.0). Average hearing loss in the impaired ear was 58.8 dB HL (SD 28.5). Over the 16-year period, 47.5% (84/177) of children showed deterioration in hearing in one or both ears from their initial diagnostic assessment to most recent assessment including 21 (11.9%) who developed bilateral hearing loss. Average deterioration in the impaired ear ranged from 27 to 31 dB with little variation across frequencies. Deterioration resulted in a change in category of severity for 67.5% (52/77) of the children. Analysis for children who were followed for at least 8 years showed that most lost a significant amount of hearing rapidly in the first 4 years, with the decrease stabilizing and showing a plateau in the last 4 years. Age and severity at diagnosis were not significantly associated with progressive/stable loss after adjusting for time since diagnosis. Etiologic factors (ENT external/middle ear anomalies, inner ear anomalies, syndromic hearing loss, hereditary/genetic) were found to be positively associated with stable hearing loss.

Conclusion

Almost half of children with UHL are at risk for deterioration in hearing in one or both ears. Most deterioration occurs within the first 4 years following diagnosis. Most children did not experience sudden "large" drops in hearing but more gradual decrease over time. These results suggest that careful monitoring of UHL especially in the early years is important to ensure optimal benefit from early hearing loss detection.

Efficacy of cochlear implants in children with borderline hearing who have already achieved significant language development with hearing aids

There are still debates about timing and effectiveness of cochlear implants (CI) in pediatric subjects with significant residual hearing who do not belong to traditional indication of CI. In this study, we aimed to investigate the outcomes of CI, specifically on improvement of pronunciation, among hearing-impaired children already with a substantial degree of language skills as evaluated by Categories of Auditory Perception (CAP) scores or sentence score. Our cohort comprised pediatric CI recipients from July 2018 through October 2020. Among them, cases with CAP scores of 5 or 6 preoperatively were defined as "borderline cases". We investigated prevalence and etiologies, and compared speech evaluation data preoperatively and postoperatively at three time points (3, 6 and 9-12 months after implantation). Among 86 pediatric CI recipients, 13 subjects (15.12%) had language development that reached CAP scores of 5 or 6 before implantation. Postoperative speech evaluation data 6 months after implantation revealed significant improvement of pronunciation (Urimal Test of Articulation and Phonation scores: UTAP), Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS) and word perception scores, but not of CAP and sentence perception scores. Notably, the significant improvement of pronunciation based on UTAP scores outstripped that of other speech parameters and this continued steadily up to one-year postoperatively. The result of the study serves as evidence for what to expect from cochlear implantation in hearing-impaired children who have already achieved a substantial degree of language development in terms of CAP scores or sentence perception scores, preoperatively.

AudioGene: refining the natural history of KCNQ4, GSDME, WFS1, and COCH-associated hearing loss

Autosomal dominant non-syndromic hearing loss (ADNSHL) displays gene-specific progression of hearing loss, which is amenable to sequential audioprofiling. We sought to refine the natural history of ADNSHL by examining audiometric data in 5-year increments. 2175 audiograms were included from four genetic causes of ADNSHL-KCNQ4 (DFNA2), GSDME (DFNA5), WFS1 (DFNA6/14/38), and COCH (DFNA9). Annual threshold deterioration (ATD) was calculated for each gene: for the speech-frequency pure tone average, the ATD, respectively, was 0.72 dB/year, 0.94 dB/year, 0.53 dB/year, and 1.41 dB/year, with the largest drops occurring from ages 45-50 (0.89 dB/year; KCNQ4), 5-10 (1.42 dB/year; GSDME), 40-45 (0.83 dB/year; WFS1), and 50-55 (2.09 dB/year; COCH). 5-year interval analysis of audiograms reveals the gene specific natural history of KCNQ4, GSDME, WFS1 and COCH-related progressive hearing loss. Identifying ages at which hearing loss is most rapid informs clinical care and patient expectations. Natural history data are also essential to define outcomes of clinical trials that test novel therapies designed to correct or ameliorate these genetic forms of hearing loss.

Age Estimate of GJB2-p.(Arg143Trp) Founder Variant in Hearing Impairment in Ghana, Suggests Multiple Independent Origins across Populations

Gap junction protein beta 2 (GJB2) (connexin 26) variants are commonly implicated in non-syndromic hearing impairment (NSHI). In Ghana, the GJB2 variant p.(Arg143Trp) is the largest contributor to NSHI and has a reported prevalence of 25.9% in affected multiplex families. To date, in the African continent, GJB2-p.(Arg143Trp) has only been reported in Ghana. Using whole-exome sequencing data from 32 individuals from 16 families segregating NSHI, and 38 unrelated hearing controls with the same ethnolinguistic background, we investigated the date and origin of p.(Arg143Trp) in Ghana using linked markers. With a Bayesian linkage disequilibrium gene mapping method, we estimated GJB2-p.(Arg143Trp) to have originated about 9625 years (385 generations) ago in Ghana. A haplotype analysis comparing data extracted from Ghanaians and those from the 1000 Genomes project revealed that GJB2-p.(Arg143Trp) is carried on different haplotype backgrounds in Ghanaian and Japanese populations, as well as among populations of European ancestry, lending further support to the multiple independent origins of the variant. In addition, we found substantial haplotype conservation in the genetic background of Ghanaian individuals with biallelic GJB2-p.(Arg143Trp) compared to the GJB2-p.(Arg143Trp)-negative group with normal hearing from Ghana, suggesting a strong evolutionary constraint in this genomic region in Ghanaian populations that are homozygous for GJB2-p.(Arg143Trp). The present study evaluates the age of GJB2-p.(Arg143Trp) at 9625 years and supports the multiple independent origins of this variant in the global population.

Cytomegalovirus-A Risk Factor for Childhood Hearing Loss: A Systematic Review

OBJECTIVE

Permanent hearing loss is an important public health issue in children with consequences for language, social, and academic functioning. Early hearing detection, intervention, and monitoring are important in mitigating the impact of permanent childhood hearing loss. Congenital cytomegalovirus (CMV) infection is a leading cause of hearing loss. The purpose of this review was to synthesize the evidence on the association between CMV infection and permanent childhood hearing loss.

DESIGN

We performed a systematic review and examined scientific literature from the following databases: MEDLINE, Ovid MEDLINE(R) Daily and Ovid MEDLINE(R), Embase, and CINAHL. The primary outcome was permanent bilateral or unilateral hearing loss with congenital onset or onset during childhood (birth to 18 years). The secondary outcome was progressive hearing loss. We included studies reporting data on CMV infection. Randomized controlled trials, quasi-experimental studies, nonrandomized comparative and noncomparative studies, and case series were considered. Data were extracted and the quality of individual studies was assessed with the Qualitative Assessment Tool for Quantitative Studies (McMaster University). The quality and strength of the evidence were graded using the Grading of Recommendations Assessment, Development and Evaluation (GRADE). A narrative synthesis was completed.

RESULTS

Sixty-five articles were included in the review. Prevalence of hearing loss at birth was over 33% among symptomatic CMV-infected newborns and less than 15% in asymptomatic infections. This difference in prevalence was maintained during childhood with more than 40% prevalence reported for symptomatic and less than 30% for asymptomatic CMV. Late-onset and progressive hearing loss appear to be characteristic of congenital CMV infections. Definitions of hearing loss, degree of loss, and reporting of laterality varied across studies. All degrees and both bilateral and unilateral loss were reported, regardless of symptomatic and asymptomatic status at birth, and no conclusions about the characteristics of hearing loss could be drawn. Various patterns of hearing loss were reported including stable, progressive, and fluctuating, and improvement in hearing (sometimes to normal hearing) was documented. These changes were reported in children with symptomatic/asymptomatic congenital CMV infection, presenting with congenital/early onset/late-onset hearing loss and in children treated and untreated with antiviral medication.

CONCLUSIONS

Symptomatic and asymptomatic congenital CMV infection should be considered a risk factor for hearing loss at birth and during childhood and for progressive hearing loss. Therefore, CMV should be included as a risk factor in screening and surveillance programs and be taken into account in clinical follow-up of children with hearing loss.

Genetic mutations in patients with nonsyndromic hearing impairment of minority and Han Chinese ethnicities in Qinghai, China

Objective

Mutations in GJB2, SLC26A4, and mitochondrial (mt)DNA 12S rRNA genes are the main cause of nonsyndromic hearing impairment. The present study analyzed these mutations in ethnic minority and Han Chinese patients with nonsyndromic hearing impairment from Qinghai, China.

Methods

The SNPscan assay was used to analyze mutation spectra and frequencies in the two patient groups.

Results

GJB2 mutations were detected in 9.5% (20/210) of minority patients and 20.88% (48/230) of Han Chinese patients. The most common Han Chinese GJB2 variants were c.235delC and c.299_300delAT, whereas c.235delC and c.109G > A were the most prevalent in minority patients. SLC26A4 mutations were detected in 5.71% (12/210) of minority patients and 14.35% (33/230) of Han Chinese patients, and mtDNA 12S rRNA mutations were detected in 4.28% (9/210) of minority patients and 9.13% (21/230) of Han Chinese patients.

Conclusions

These data indicate that the mutation frequencies of three deafness-associated genes were significantly higher in Han Chinese patients than in minority patients. Moreover, the GJB2 mutation spectrum was shown to differ between these two patient groups.

Etiology of early hearing loss in Brazilian children

INTRODUCTION

Hearing loss etiology depends on the population studied as well as on the ethnicity and the socio-economic condition of the analyzed region. Etiological diagnosis contributes to the improvement of preventive measures and to the early identification of this deficiency.

OBJECTIVE

To identify the etiological factors of hearing loss and its prevalence in a tertiary hospital in southern Brazil, to verify the frequency of mutations in GJB2 and GJB6 genes, and to correlate the degree of hearing loss with the etiological factors of deafness.

METHODS

This prevalence study involved 140 children with bilateral sensorineural or mixed hearing loss. Medical history, physical examination, audiometry, and evoked auditory brainstem response were conducted. Imaging and genetic examinations were also performed.

RESULTS

Etiologies and their prevalence were as follows: (a) indeterminate causes, 31.4%; (b) conditions related to neonatal period, 22.1%; (c) genetic, 22.1%; (d) auditory neuropathy, 10%; (e) other factors (cortical malformation, intracranial hemorrhage, and internal ear malformations), 7.9% and (f) congenital infections, 6.4%. Within the genetic cases, ten homozygous and seven heterozygotes of the 35delG mutation were identified, besides two cases of rare variants of GJB2: p.Try172* and p.Arg184Pro. One case with homozygosis of del(GJB6-D13S1830) was found. Regarding severity of hearing loss, in 78.6% of the cases the degree of hearing loss was profound and there were no significant differences when comparing between etiologies.

CONCLUSION

The number of indeterminate etiologies is still high and congenital CMV infection may be a possible cause of undiagnosed etiology for hearing loss. The predominance of etiologies related to neonatal conditions and infectious causes are characteristic of developing countries. The most prevalent mutation was 35delG, the main GJB2 gene, probably because of the European influence in the genotype of our population.

Molecular diagnosis of SLC26A4-related hereditary hearing loss in a group of patients from two provinces of Iran

The SLC26A4 gene has been described as the second gene involved in most cases of autosomal recessive non-syndromic hearing loss (ARNSHL), after GJB2. Over 500 different SLC26A4 mutations have been reported, with each ethnic population having its own distinctive mutations. Here, we aimed to determine the frequency and mutation profile of the SLC26A4 gene from two different provinces (center and west) of Iran. This study included 50 nuclear families with two or more siblings segregating presumed ARNSHL. All affected tested negative for mutations in GJB2 at the DFNB1 locus and were therefore screened for autozygosity by descent using short tandem repeat polymorphisms (STRPs) of DFNB4. Sanger sequencing was performed to screen the 20 exons of the SLC26A4 gene for the families linked to this locus. In silico analyses were also performed using available software tools. Four out of 25 (16%) and 3 of 25 (12%) studied families of Isfahan and Hamedan provinces, respectively. were linked to DFNB4. Sanger sequencing led to the identification of six different mutations, one of which (c.919-2A>G) was recurrent and accounted for 31% of all mutant alleles. One out of 7 (14.3%) families with mutations were confirmed to be Pendred syndrome (PS). The SLC26A4 mutations have a high carrying rate in ARNSHL Iranian patients. The identification of a disease causing mutation can be used to establish a genotypic diagnosis and provide important information to the patients and their families.

Etiology of Prelingual Hearing Loss in the Universal Newborn Hearing Screening Era: A Scoping Review

OBJECTIVE

To conduct a scoping review on etiologic investigation of prelingual hearing loss among children <2 years of age in the era of universal newborn hearing screening (UNHS).

DATA SOURCES

PubMed, Embase, PsycInfo, CINAHL, and Cochrane Library databases.

REVIEW METHODS

We searched for articles published from January 1, 1998, to February 19, 2020. We reviewed studies that (1) included children identified with either congenital or delayed-onset hearing loss before 2 years of age among cohorts who had undergone UNHS and (2) investigated ≥1 etiologies of hearing loss. We defined hearing loss as congenital when confirmed after UNHS failure and as delayed onset when diagnosed after ≥1 assessments with normal hearing.

RESULTS

Among 2069 unique citations, 115 studies met criteria for full-text assessment, and 20 met our inclusion criteria. Six studies tested children diagnosed with hearing loss for genetic etiology, 9 for congenital cytomegalovirus (CMV) infection, and 5 for both. Among 1787 children with congenital hearing loss and etiologic investigation, 933 (52.2%) were tested for genetic mutations and 1021 (57.1%) for congenital CMV infection. The proportion of congenital hearing loss cases attributable to genetic etiology ranged between 7.7% and 83.3% and to congenital CMV infection between 0.0% and 32.0%.

CONCLUSION

Data are lacking on the identification and etiology of delayed-onset hearing loss in children <2 years of age in the UNHS era. The proportion of congenital hearing loss cases attributable to genetic etiologies and congenital CMV infection appears to vary widely.

Genetic Testing for Congenital Bilateral Hearing Loss in the Context of Targeted Cytomegalovirus Screening

OBJECTIVES/HYPOTHESIS

To determine the prevalence of children with genetic hearing loss who are cytomegalovirus (CMV) positive at birth and the relative proportion of genetic and CMV etiology among children with congenital bilateral hearing loss.

STUDY DESIGN

Database review.

METHODS

We performed a review of clinical test results for patients undergoing comprehensive genetic testing for all known hearing loss-associated genes from January 2012 to January 2019. This population was reviewed for reported CMV status and genetic causes of congenital bilateral hearing loss.

RESULTS

In the OtoSCOPE database, 61/4,282 patients were found to have a documented CMV status, and 661/4282 had documented bilateral congenital hearing loss. Two patients were identified who had both a positive CMV result and a genetic cause for their hearing loss. Forty-eight percent of patients with bilateral congenital hearing loss (320/661) were found to have a genetic etiology. In 62% (198/320), the hearing loss was associated with pathogenic variants in GJB2, STRC, SLC26A4 or an Usher syndrome-associated gene.

CONCLUSIONS

We estimate that ~2% of CMV-positive newborns with hearing loss have a known genetic variant as a cause. The subcohort of CMV-positive newborns with symmetric mild-to-moderate bilateral hearing loss will have at least a 7% chance of having pathogenic gene variants associated with hearing loss. In a CMV-positive neonate who failed their newborn hearing screen bilaterally, genetic screening needs to be considered for accurate diagnosis and possible deferment of antiviral treatment.

LEVEL OF EVIDENCE

4 Laryngoscope, 130:2714-2718, 2020.

Progressive Hearing Loss in Children With Mild Bilateral Hearing Loss

Purpose This study investigated progressive hearing loss in a cohort of children who were identified with permanent mild bilateral hearing loss. Method This population-based study included 207 children with permanent mild bilateral hearing loss, diagnosed and followed from 2003 to 2016 in 1 region of Canada. Clinical characteristics and initial audiologic results were collected prospectively at diagnosis, and audiologic information was updated. Changes in hearing levels between the 1st and most recent assessment were analyzed to determine progressive hearing loss. Clinical characteristics were compared between children with progressive and stable hearing loss. The association between risk indicators and progressive hearing loss was explored through logistic regression. Results A total of 47.4% (94 of 207) had progressive hearing loss in at least 1 ear, and 50% (47 of 94) of those experienced more than 20-dB average drop in thresholds. For these 94 children, a total of 147 ears were affected, and 116 (78.9%) ears experienced sufficient change in thresholds to be coded as a worse category of hearing loss. In the subset of 85 children with more than 5 years of audiologic follow-up, 56.4% (53/85) showed a decrease in hearing. Of the total sample of 207 children, 137 (66.2%) continued to have mild hearing loss in the better ear. There was no association between the risk factors examined (family history of hearing loss, admission to the neonatal intensive care unit, or presence of a syndrome) and progressive hearing loss. Conclusion This study found that almost half of children with mild bilateral hearing loss showed a decrease in hearing in at least 1 ear. One third of the children first diagnosed with mild hearing loss in the better ear now have moderate or worse hearing loss in both ears. These findings point to the importance of careful long-term monitoring of children who present with mild hearing loss.

Should You Follow the Better-Hearing Ear for Congenital Cytomegalovirus Infection and Isolated Sensorineural Hearing Loss?

OBJECTIVE

To describe the progression of sensorineural hearing loss (SNHL) in the better- and poorer-hearing ears in children with asymptomatic congenital cytomegalovirus (CMV) infection with isolated SNHL.

STUDY DESIGN

Longitudinal prospective cohort study.

SETTING

Tertiary medical center.

SUBJECTS AND METHODS

We analyzed hearing thresholds of the better- and poorer-hearing ears of 16 CMV-infected patients with isolated congenital/early-onset or delayed-onset SNHL identified through hospital-based CMV screening of >30,000 newborns from 1982 to 1992.

RESULTS

By 12 months of age, 4 of 7 patients with congenital/early-onset SNHL developed worsening thresholds in the poorer-hearing ear, and 1 had an improvement in the better-hearing ear. By 18 years of age, all 7 patients had worsening thresholds in the poorer-hearing ear and 3 patients had worsening thresholds in the better-hearing ear. Hearing loss first worsened at a mean age of 2 and 6 years in the poorer- and better-hearing ears, respectively. Nine patients were diagnosed with delayed-onset SNHL (mean age of 9 years vs 12 years for the poorer- and better-hearing ears), 6 of whom had worsening thresholds in the poorer-hearing ear and 1 in both ears.

CONCLUSION

In most children with congenital CMV infection and isolated SNHL, the poorer-hearing ear worsened earlier and more precipitously than the better-hearing ear. This study suggests that monitoring individual hearing thresholds in both ears is important for appropriate interventions and future evaluation of efficacy of antiviral treatment.

Distribution of the CMV glycoprotein gH/gL/gO and gH/gL/pUL128/pUL130/pUL131A complex variants and associated clinical manifestations in infants infected congenitally or postnatally

Human cytomegalovirus (CMV) is a major cause of morbidity in fetuses following intrauterine infection. The glycoprotein (g) envelope trimeric gH/gL/gO and pentameric gH/gL/pUL128/pUL130/pUL131A complexes are required for CMV entry into fibroblasts and endothelial/epithelial cells, respectively, and both are targets for neutralizing antibodies. The role of sequence variability among viral strains in the outcome of congenital CMV infection is controversial. Variation in the CMV UL75 gene encoding glycoprotein H (gH), the UL115 (gL), the UL74 (gO), and the UL128 locus (UL128L) encoding three structural proteins (pUL128, pUL130, and pUL131A) was determined in 82 newborns with congenital CMV infection and 113 infants with postnatal or unproven congenital CMV infection. Genotyping was performed by sequencing analysis of PCR-amplified fragments and the PCR-restriction fragment length polymorphism (RFLP) method, and the viral load was measured by quantitative real-time PCR. The obtained results demonstrated that (1) different CMV variants and mixed CMV infections can be detected in newborns infected congenitally; (2) the gH1 genotype, UL130 variant 6, and UL131A variant 1 were associated with some signs/symptoms within cohort of pediatric patients, mainly consisting of infants with symptomatic CMV infection. The results revealed that pUL130, pUL131A, and gH polymorphisms seemed to be associated with the outcome of CMV infection in infants.

A systematic review of SLC26A4 mutations causing hearing loss in the Iranian population

OBJECTIVES

The genetics of sensorineural hearing loss is characterized by a high degree of heterogeneity. In spite of this, mutations in the SLC26A4 gene, have been reported to be the second most common contributor after those of GJB2 in many populations. However, different results have been reported for the frequency of SLC26A4 mutations in Iran, which varies between 0 and 12.3%. Here, we have taken together and reviewed the spectrum and frequency of the reported SLC26A4 mutations to provide a comprehensive collection of data for SLC26A4 mutations and HL in the Iranian population and considered founder mutations.

METHODS

A systematic literature review of the PubMed, Google Scholar, Web of Science, and Science Direct databases was conducted for articles published before March 2019. The primary data of these studies including the number of samples, mutation frequency and so on were extracted.

RESULTS

Nine studies involved 827 unrelated families were included and analyzed for the type and prevalence of the SLC26A4 gene mutations. Altogether 39 different genetic mutations were detected. SLC26A4 mutations were found to be 6.39% in the population studied which is significantly lower than that identified in the east Asia. However, c.1334T > G was the most common mutation accounting for 10% of the populations studied.

CONCLUSIONS

This data gives an overview of the SLC26A4 mutations in Iran, which could be used for screening, diagnostic programs of live births and genetic counseling.

Risk factors for hearing loss in children: a systematic literature review and meta-analysis protocol

BACKGROUND

Hearing loss in newborns and children is a public health concern, due to high prevalence and negative effects on their development. Early detection and intervention of childhood hearing loss may mitigate these negative effects. Population-based newborn hearing screening programs have been established worldwide to identify children at risk for congenital hearing loss and to follow children at risk for late onset or progressive hearing loss. This article presents the protocol for a systematic review that aims to review the risk factors associated with permanent hearing loss in children, including congenital, early, or late onset. Risk factors associated with progressive hearing loss will be investigated as a secondary aim.

METHODS

Scientific literature from the following databases will be investigated: MEDLINE, Ovid MEDLINE(R) Daily and Ovid MEDLINE(R), Embase, and CINAHL. The primary outcome is a permanent bilateral or unilateral hearing loss with congenital onset or onset during childhood (birth to 18 years). The secondary outcome is progressive hearing loss. Studies must report data on risk factors associated with permanent hearing loss; risk factors may be present at birth or later and result in immediate or delayed hearing loss. Randomized controlled trials, quasi-experimental studies, nonrandomized comparative and non-comparative studies, and case series will be included. The risk of bias will be assessed using the Qualitative Assessment Tool for Quantitative Studies (McMaster University). If aggregation of data is possible for a subsection of studies, we will pool data using meta-analysis techniques. If aggregation of data is not possible, a qualitative synthesis will be presented. We will assess the quality and strength of the overall body of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE). The systematic review follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations.

DISCUSSION

The resulting information will inform the update of a provincial audiological surveillance protocol for the Ontario Infant Hearing Program and will be applicable to early hearing detection and intervention (EHDI) programs worldwide.

SYSTEMATIC REVIEW REGISTRATION

We have registered the protocol in the International Prospective Register of Systematic Reviews (PROSPERO), registration number CRD42018104121.

Recognition, treatment, and sequelae of congenital cytomegalovirus in Australia: An observational study

BACKGROUND AND OBJECTIVES

Australian national surveillance data was used to assess recognition, sequelae, and antiviral therapy for congenital cytomegalovirus (CMV) cases.

STUDY DESIGN

Data from congenital CMV cases reported through the Australian Paediatric Surveillance Unit born January 1999 to December 2016 were described and Chi-square tests used to characterise trends and associations in case reporting, maternal CMV serology testing, and antiviral therapy. Descriptive analyses for hearing loss and developmental delay were reported for cases born ≥2004, following introduction of universal neonatal hearing screening.

RESULTS

There were 302 congenital CMV cases (214 symptomatic, 88 asymptomatic). Congenital CMV was suspected in 70.6% by 30 days of age, with no differences across birth cohorts. Maternal CMV serology testing was associated with maternal illness during pregnancy but not birth cohort. There was increasing antiviral use for symptomatic cases, being used in 14% born 1999-2004, 19.6% born 2005-2010, and 44.4% born 2011-2016 (p < 0.001). For those born ≥2004, hearing loss was reported in 42.1% of symptomatic and 26.6% of asymptomatic cases; while developmental delay was reported in 16.9% of symptomatic and 1.3% of asymptomatic cases.

CONCLUSION

There appears to be under-reporting and under-recognition of congenital CMV despite increasing use of antiviral therapy. Universal newborn CMV screening should be considered to facilitate follow-up of affected children and targeted linkage into hearing and developmental services, and to provide population-level infant CMV epidemiology to support research and evaluation of antiviral and adjunctive therapies.

Neonates with congenital Cytomegalovirus and hearing loss identified via the universal newborn hearing screening program

BACKGROUND

Congenital cytomegalovirus (CMV) is the most common non-genetic cause of sensorineural hearing loss. Currently, there are no universal CMV screening programs for newborns or routine CMV testing of neonates with hearing loss in Australia, or elsewhere.

OBJECTIVES

This study was undertaken to determine the prevalence of congenital CMV infection in infants with hearing loss identified using routine resources via the Australian universal neonatal hearing screening (UNHS) program.

STUDY DESIGN

Infants who failed UNHS, referred for audiological testing and found to have permanent hearing loss were screened for CMV via PCR of urine and saliva. Congenital CMV was diagnosed if CMV was detected in infants ≤30 days of age, or using retrospective testing on stored new born screening cards, retrospective testing, or using clinical criteria if >30 days of age. The cohort was analyzed for time of testing and prevalence of congenital CMV determined.

RESULTS

The Audiology Department reviewed 1669 infants who failed UNHS between 2009 and 2016. Thirty percent (502/1669) had permanent hearing loss confirmed, of whom 336/502 were offered CMV testing. A definite (n = 11) or probable (n = 8) diagnosis of congenital CMV occurred in 19/323 (5.9%), of whom definite diagnoses were made in 4/19 on tests positive prior to 21 days of life, in 5/19 who were positive on neonatal blood screening card (NBSC) testing, in 2/19 who were positive on placental testing. In 8/19 probable diagnoses were made based on positive testing between ages 23-42 days and a consistent clinical syndrome in the absence of another cause for hearing loss after genetic and other testing. CMV testing mirrored the timing of audiological testing, with ∼40% completing audiology and CMV testing by 21 days, and 64% by 30 days.

CONCLUSION

This program, utilizing existing clinical services identified probable congenital CMV in ∼6% of a large cohort failing UNHS with permanent hearing loss, of whom more than half were definite diagnoses. No additional assets were required to those already existing in this tertiary referral pediatric centre, whilst providing useful and timely data for clinical and audiological management.

Programming characteristics of cochlear implants in children: effects of aetiology and age at implantation

OBJECTIVE

We investigated effects of aetiology and age at implantation on changes in threshold (T) levels, comfortable (C) levels and dynamic range (DR) for cochlear implants (CIs) in children over the first five years of life.

DESIGN

Information was collected at 6 months post-activation of CIs, and at 3 and 5 years of age.

STUDY SAMPLE

One hundred and sixty-one children participating in the Longitudinal Outcomes of Children with Hearing Impairment (LOCHI) study.

RESULTS

Children with neural and structural cochlear lesions had higher T-levels and C-levels as compared to those without these conditions. Parameter settings varied from manufacturer's defaults more often in the former than in the latter group. Investigation of the effect of age at implantation for children without neural and structural cochlear lesions showed that those implanted at ≤12 months of age had higher T-levels and narrower DR at 6 months post-activation, as compared to the later-implanted group. For both early- and later-implanted groups, the C-levels at 6 months post-activation were lower than those at age 3 and 5 years. There were no significant differences in T-levels, C-levels, or DR between age 3 and 5 years.

CONCLUSIONS

Aetiology and age at implantation had significant effects on T-levels and C-levels.

Hearing and neurodevelopmental outcomes for children with asymptomatic congenital cytomegalovirus infection: A systematic review

INTRODUCTION

Congenital CMV is one of the commonest congenital infections and a recognised cause of sensorineural hearing loss and neurodevelopmental impairment. Ninety percent are clinically inapparent at birth but are reported to be at risk of developing such abnormalities throughout childhood, the extent of which requires further elucidation.

METHODS

A systematic literature review was conducted using Medline and Embase databases, manual citation review, and personal libraries for articles reporting primary data on hearing and neurodevelopmental outcomes for children with asymptomatic congenital CMV. PROSPERO registration number CRD42015025407.

RESULTS

Thirty-seven of 480 articles identified between 1969 and 2016 met the eligibility criteria. Twenty-nine of these contributed primary data on hearing outcomes and 20 on neurodevelopmental outcomes (12 of the 37 studies contributed data on both). Cumulative incidence of sensorineural hearing loss with follow-up to at least 5 years was 7% to 11%, which is more than healthy controls but less than children with symptomatic congenital CMV (34%-41%). The onset, course, and severity of hearing loss was variable with no reliable virological prognostic marker. In comparison to controls, children with asymptomatic congenital CMV did not perform worse than controls in neurodevelopmental assessments and performed better than children with symptomatic congenital CMV.

CONCLUSIONS

Studies show children with asymptomatic congenital CMV are at increased risk of developing hearing loss but perform equally well on neurodevelopmental assessments when compared with healthy controls. There is no reliable virological marker to determine which infants will develop sequelae. Regular follow-up until school entry is supported by the literature.

Characteristics of children with unilateral hearing loss

OBJECTIVE

The purpose of this study was to describe the clinical characteristics of children with unilateral hearing loss (UHL), examine deterioration in hearing, and explore amplification decisions.

DESIGN

Population-based data were collected prospectively from time of diagnosis. Serial audiograms and amplification details were retrospectively extracted from clinical charts to document the trajectory and management of hearing loss.

SAMPLE

The study included all children identified with UHL in one region of Canada over a 13-year period (2003-2015) after implementation of universal newborn hearing screening.

RESULTS

Of 537 children with permanent hearing loss, 20.1% (108) presented with UHL at diagnosis. They were identified at a median age of 13.9 months (IQR: 2.8, 49.0). Children with congenital loss were identified at 2.8 months (IQR: 2.0, 3.6) and made up 47.2% (n = 51), reflecting that a substantial portion had late-onset, acquired or late-identified loss. A total of 42.4% (n = 39) showed deterioration in hearing, including 16 (17.4%) who developed bilateral loss. By study end, 73.1% (79/108) of children had received amplification recommendations.

CONCLUSIONS

Up to 20% of children with permanent HL are first diagnosed with UHL. About 40% are at risk for deterioration in hearing either in the impaired ear and/or in the normal hearing ear.

Spectrum and Frequency of the GJB2 Gene Pathogenic Variants in a Large Cohort of Patients with Hearing Impairment Living in a Subarctic Region of Russia (the Sakha Republic)

Pathogenic variants in the GJB2 gene, encoding connexin 26, are known to be a major cause of hearing impairment (HI). More than 300 allelic variants have been identified in the GJB2 gene. Spectrum and allelic frequencies of the GJB2 gene vary significantly among different ethnic groups worldwide. Until now, the spectrum and frequency of the pathogenic variants in exon 1, exon 2 and the flanking intronic regions of the GJB2 gene have not been described thoroughly in the Sakha Republic (Yakutia), which is located in a subarctic region in Russia. The complete sequencing of the non-coding and coding regions of the GJB2 gene was performed in 393 patients with HI (Yakuts—296, Russians—51, mixed and other ethnicities—46) and in 187 normal hearing individuals of Yakut (n = 107) and Russian (n = 80) populations. In the total sample (n = 580), we revealed 12 allelic variants of the GJB2 gene, 8 of which were recessive pathogenic variants. Ten genotypes with biallelic recessive pathogenic variants in the GJB2 gene (in a homozygous or a compound heterozygous state) were found in 192 out of 393 patients (48.85%). We found that the most frequent GJB2 pathogenic variant in the Yakut patients was c.-23+1G>A (51.82%) and that the second most frequent was c.109G>A (2.37%), followed by c.35delG (1.64%). Pathogenic variants с.35delG (22.34%), c.-23+1G>A (5.31%), and c.313_326del14 (2.12%) were found to be the most frequent among the Russian patients. The carrier frequencies of the c.-23+1G>A and с.109G>A pathogenic variants in the Yakut control group were 10.20% and 2.80%, respectively. The carrier frequencies of с.35delG and c.101T>C were identical (2.5%) in the Russian control group. We found that the contribution of the GJB2 gene pathogenic variants in HI in the population of the Sakha Republic (48.85%) was the highest among all of the previously studied regions of Asia. We suggest that extensive accumulation of the c.-23+1G>A pathogenic variant in the indigenous Yakut population (92.20% of all mutant chromosomes in patients) and an extremely high (10.20%) carrier frequency in the control group may indicate a possible selective advantage for the c.-23+1G>A carriers living in subarctic climate.

Universal newborn hearing screening in Umbria region, Italy

OBJECTIVE

In Italy, universal newborn hearing screening (UNHS) was first introduced in some regions from 1997. Umbria Region has launched a UNHS program in all hospitals, which has been implemented throughout the region since July 2010. Before UNHS implementation in Umbria region, the average age of identification of congenital hearing loss was around 32 months of age with an average age of initial amplification treatment at least 2 months later. The coverage rate of newborn screening was only 34.4% in 2006. The aim of this study was to examine the results of this program and its evolution in the first 2.5 years since implementation in our region.

METHODS

Since July 2010, all 11 birth centers and hospitals in Umbria region have been involved in a UNHS program. The screening involves the automated otoacoustic emissions (AOAE) test and automatic auditory brain stem response (AABR) audiometry. The number of screening stages and tests used were different depending on whether the infants had audiological risk factors or not.

RESULTS

A total of 20,841 babies were born in the hospitals involved of whom 20,051 were well born babies (WB), while 790 babies (3.8%) presented identified audiological risk factors (BRF). The overall coverage rate in the study period was 93.8%. The prevalence of hearing loss was 2‰ for WB infants and 4.3% for BRF. Mean age at diagnosis was 5.31±3.95 and 11.28±7.73 months in the WB and BRF groups, respectively.

CONCLUSIONS

UNHS has allowed us to substantially increase the coverage rates and decrease the mean age at diagnosis and subsequent treatment. The identification of audiological risk factors is very important for adequate screening and follow-up. However the Joint Committee on Infant Hearing 2007 quality indicators and benchmarks for screening have not yet been fully achieved and there is still scope for some improvement. This could be achieved with a closer cooperation among institutions, parents, pediatricians, and ENT doctors.

Congenital cytomegalovirus infection in pregnancy: a review of prevalence, clinical features, diagnosis and prevention

Human cytomegalovirus (CMV) is under-recognised, despite being the leading infectious cause of congenital malformation, affecting ~0.3% of Australian live births. Approximately 11% of infants born with congenital CMV infection are symptomatic, resulting in clinical manifestations, including jaundice, hepatosplenomegaly, petechiae, microcephaly, intrauterine growth restriction and death. Congenital CMV infection may cause severe long-term sequelae, including progressive sensorineural hearing loss and developmental delay in 40-58% of symptomatic neonates, and ~14% of initially asymptomatic infected neonates. Up to 50% of maternal CMV infections have nonspecific clinical manifestations, and most remain undetected unless specific serological testing is undertaken. The combination of serology tests for CMV-specific IgM, IgG and IgG avidity provide improved distinction between primary and secondary maternal infections. In pregnancies with confirmed primary maternal CMV infection, amniocentesis with CMV-PCR performed on amniotic fluid, undertaken after 21-22 weeks gestation, may determine whether maternofetal virus transmission has occurred. Ultrasound and, to a lesser extent, magnetic resonance imaging are valuable tools to assess fetal structural and growth abnormalities, although the absence of fetal abnormalities does not exclude fetal damage. Diagnosis of congenital CMV infection at birth or in the first 3 weeks of an infant's life is crucial, as this should prompt interventions for prevention of delayed-onset hearing loss and neurodevelopmental delay in affected infants. Prevention strategies should also target mothers because increased awareness and hygiene measures may reduce maternal infection. Recognition of the importance of CMV in pregnancy and in neonates is increasingly needed, particularly as therapeutic and preventive interventions expand for this serious problem.

Ethnic-specific spectrum of GJB2 and SLC26A4 mutations: their origin and a literature review

OBJECTIVE

The mutation spectrum of the GJB2 and SLC26A4 genes, the 2 most common genes causing deafness, are known to be ethnic specific. In this study, the spectrum of the reported GJB2 and SLC26A4 mutations in different populations are reviewed and considered from a human migration perspective.

METHODS

Fifty-two and 17 articles on GJB2 and SLC26A4 mutations, respectively, were reviewed through the PubMed database from April 1996 to September 2014. The 4 most prevalent mutations were selected and compared. A cluster analysis was subsequently performed for these selected mutations.

RESULTS

The present review of frequent mutations shows the ethnic-specific GJB2 and SLC26A4 gene mutation spectrum. A cluster analysis of the GJB2 and SLC26A4 genes revealed similarities between ethnic populations.

CONCLUSION

The mutation spectrum reviewed in this study clearly indicated that the frequent mutations in the GJB2 and SLC26A4 genes are consistent with the founder mutation hypothesis. A comparison with the Y-chromosome phylogenetic tree indicated that these mutations may have occurred during human migration.

HCMV seroprevalence in couples under infertility treatment

PURPOSE

Congenital HCMV infection affects about 0.5-0.9 % of newborns in Europe. Primary prevention could effectively be implemented in screening programmes for couples treated for infertility. By supplying epidemiological data, the proportion of women susceptible to primary HCMV infection is estimated.

METHODS

Retrospective evaluation of HCMV IgG of couples with recurrent implantation failure in German IVF programmes referred to a tertiary immunological centre for lymphocyte immunotherapy in 2002 (727 couples) and 2012 (294 male partners only).

RESULTS

HCMV seroprevalence was 45 % in women and 33 % in men of childbearing age in 2002 and has not declined any further in the male group (34 %) in 2012. It was higher in women (39.8 %) than in males (28.0 %) of German descent (p < 0.00001). Most couples were concordantly seropositive (20.5 %) or negative (41.8 %). Discordant partnerships comprised of seropositive women with negative partners (24.6 %) and seronegative women with positive partners (13.1 %).

CONCLUSIONS

More than 50 % of the women are HCMV seronegative and may benefit from primary prevention. About one fourth of them live with a seropositive partner. Risks to contract HCMV via the sexual route in a long-term discordant partnership may be very low, and the advice of protective safer sex methods in this group of prospective parents is critical since it leads to a conflict of interests.

Clinical and epidemiological features of congenital cytomegalovirus infection globally

Human cytomegalovirus (CMV) is the most common non-genetic cause of congenital disability. As a herpesvirus that infects the majority of the population, CMV is able to establish a lifelong latent infection in the host. Any time during pregnancy, a primary CMV infection, reactivation of latent CMV or a new viral strain can infect the placenta and the developing foetus, resulting in congenital CMV infection. Each year, an estimated 2000 children are born with congenital CMV infection in Australia, leaving ~500 children with permanent disabilities such as hearing or vision loss, or mental disability. Despite the clinical importance of congenital CMV, there is limited awareness and knowledge in the medical and general community about congenital CMV infection. This article reviews the global epidemiology and clinical features of maternal and congenital CMV infections.

Congenital cytomegalovirus infection: Clinical presentation, epidemiology, diagnosis and prevention

Cytomegalovirus is the most common congenital infection causing serious disease in infants. It is the leading infectious cause of sensorineural hearing loss and neurodevelopmental disability in developed countries. Despite the clinical importance of congenital cytomegalovirus, surveys show there is limited awareness and knowledge in the medical and general community about congenital cytomegalovirus infection. This article reviews the clinical features, global epidemiology, transmission and risk factors for cytomegalovirus infections. It also highlights several major advances made in recent years in the diagnosis and prevention of cytomegalovirus infection during pregnancy. Although research is ongoing, no therapy is currently proven to prevent or treat maternal, fetal or neonatal cytomegalovirus infection. Education of women regarding hygiene measures can help prevent cytomegalovirus infection and are currently the best strategy to prevent congenital cytomegalovirus disease.

Vestibular function in children with auditory neuropathy spectrum disorder

OBJECTIVE

Children with auditory neuropathy spectrum disorder (ANSD) account for about 10% of paediatric patients referred for cochlear implantation. Vestibulopathy may be associated with ANSD, and may have implications when formulating management plans in this patient group. We wanted to determine the incidence and predictive factors for vestibulopathy in this patient group to guide vestibular testing in this patient population, and give insight to the aetiology of ANSD.

METHODS

We reviewed the outcomes of vestibular function testing in a cohort of paediatric patients with ANSD.

RESULTS

Probable or definite vestibulopathy was seen in 42% of patients who were tested. Vestibulopathy was associated with medical co-morbidities, but was not associated with imaging findings.

CONCLUSIONS

Vestibulopathy is relatively prevalent in this patient group, and should be considered when planning the investigation and management of children with ANSD.

Second stage of Universal Neonatal Hearing Screening - a way for diagnosis and beginning of proper treatment for infants with hearing loss

PURPOSE

To analyze retrospectively the results of hearing testing in infants at the second stage of the Polish Universal Neonatal Hearing Screening Program carried out in the Department of Otolaryngology at the Medical University of Warsaw.

MATERIAL/METHODS

A total of 351 infants referred to our Department for the second stage of UNHS were included in the study. There were 39.60% infants referred due to positive result of hearing screening at the first stage of the Program performed in neonatal units, 55.27% with negative screening but risk factors present, and 5.13% without any tests due to equipment failure in the maternity unit.

RESULTS

Risk factors were identified in 86.61% of the infants. The most frequent ones were hyperbilirubinemia (71.51%), premature birth (63.25%), and ototoxic medication (62.11%). Otoacoustic emission test showed fail results in 17.66% of the infants, and auditory brainstem responses confirmed hearing loss in 16.81%. Correlation between risk factors and confirmed hearing loss was found for hyperbilirubinemia, low birth weight, intensive therapy for at least 7 days, low Apgar scores, and craniofacial abnormalities.

CONCLUSIONS

The early identification of infants with hearing loss is essential for early intervention. Not only infants who fail the initial screening but also the ones with risk factors of hearing impairment should be referred to the centers that are capable of providing the necessary diagnostic services required for the second stage of the UNHSP. Those two steps are needed to both minimize the risk of overlooking a child with hearing loss and properly diagnose hearing impairment.

Impact of the presence of auditory neuropathy spectrum disorder (ANSD) on outcomes of children at three years of age

OBJECTIVE

To determine the influence of the presence of auditory neuropathy spectrum disorder (ANSD) on speech, language, and psycho-social development of children at three years of age.

DESIGN

A population-based, longitudinal study was performed on outcomes of children with hearing impairment (LOCHI) in Australia. The demographic characteristics of the children were described, and their developmental outcomes were evaluated at three years of age. Performance of children with ANSD was compared with that of children without ANSD in the LOCHI study.

STUDY SAMPLE

There were 47 children with ANSD in the study sample.

RESULTS

Sixty-four percent of children with ANSD have hearing sensitivity loss ranging from mild to severe degree, and the remaining have profound hearing loss. At three years, 27 children used hearing aids, 19 used cochlear implants, and one child did not use any hearing device. Thirty percent of children have disabilities in addition to hearing loss. On average, there were no significant differences in performance level between children with and without ANSD. Also, the variability of scores was not significantly different between the two groups.

CONCLUSIONS

There was no significant difference in performance levels or variability between children with and without ANSD, both for children who use hearing aids, and children who use cochlear implants.