Diagnostic yield in the workup of congenital sensorineural hearing loss is dependent on patient ethnicity

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.

Use of Diagnostic Testing and Intervention for Sensorineural Hearing Loss in US Children From 2008 to 2018

Importance

Early detection and intervention of pediatric hearing loss is critical for language development and academic achievement. However, variations in the diagnostic workup and management of pediatric sensorineural hearing loss (SNHL) exist.

Objective

To identify patient and clinician factors that are associated with variation in practice on a national level.

Design, Setting, and Participants

This cross-sectional study used the Optum claims database to identify 53 711 unique children with SNHL between January 1, 2008, and December 31, 2018.

Main Outcomes and Measures

National use rates and mean costs for diagnostic modalities (electrocardiogram, cytomegalovirus testing, magnetic resonance imaging, computed tomography, and genetic testing) and interventions (speech-language pathology, billed hearing aid services, and cochlear implant surgery) were reported. The associations of age, sex, SNHL laterality, clinician type, race/ethnicity, and household income with diagnostic workup and intervention use were measured in multivariable analyses.

Results

Of 53 711 patients, 23 735 (44.2%) were girls, 2934 (5.5%) were Asian, 3797 (7.1%) were Black, 5626 (10.5%) were Hispanic, 33 441 (62.3%) were White, and the mean (SD) age was 7.3 (5.3) years. Of all patients, 32 200 (60.0%) were seen by general otolaryngologists, while 7573 (14.10%) were seen by pediatric otolaryngologists. Diagnostic workup was received by 14 647 patients (27.3%), while 13 482 (25.1%) received intervention. Use of genetic testing increased (odds ratio, 1.22 per year; 95% CI, 1.20-1.24), whereas use of computed tomography decreased (odds ratio, 0.93 per year; 95% CI, 0.92-0.94) during the study period. After adjusting for relevant covariables, children who were seen by pediatric otolaryngologists and geneticists had the highest odds of receiving workup and intervention. Additionally, racial/ethnic and economic disparities were observed in the use of most modalities of diagnostic workup and intervention for pediatric SNHL.

Conclusions and Relevance

This cross-sectional study identified factors associated with disparities in the diagnostic workup and intervention of pediatric SNHL, thus highlighting the need for increased education and standardization in the management of this common sensory disorder.

Medical Referral Patterns and Etiologies for Children With Mild-to-Severe Hearing Loss

OBJECTIVES

To (1) identify the etiologies and risk factors of the patient cohort and determine the degree to which they reflected the incidence for children with hearing loss and (2) quantify practice management patterns in three catchment areas of the United States with available centers of excellence in pediatric hearing loss.

DESIGN

Medical information for 307 children with bilateral, mild-to-severe hearing loss was examined retrospectively. Children were participants in the Outcomes of Children with Hearing Loss (OCHL) study, a 5-year longitudinal study that recruited subjects at three different sites. Children aged 6 months to 7 years at time of OCHL enrollment were participants in this study. Children with cochlear implants, children with severe or profound hearing loss, and children with significant cognitive or motor delays were excluded from the OCHL study and, by extension, from this analysis. Medical information was gathered using medical records and participant intake forms, the latter reflecting a caregiver's report. A comparison group included 134 children with normal hearing. A Chi-square test on two-way tables was used to assess for differences in referral patterns by site for the children who are hard of hearing (CHH). Linear regression was performed on gestational age and birth weight as continuous variables. Risk factors were assessed using t tests. The alpha value was set at p < 0.05.

RESULTS

Neonatal intensive care unit stay, mechanical ventilation, oxygen requirement, aminoglycoside exposure, and family history were correlated with hearing loss. For this study cohort, congenital cytomegalovirus, strep positivity, bacterial meningitis, extracorporeal membrane oxygenation, and loop diuretic exposure were not associated with hearing loss. Less than 50% of children underwent imaging, although 34.2% of those scanned had abnormalities identified. No single imaging modality was preferred. Differences in referral rates were apparent for neurology, radiology, genetics, and ophthalmology.

CONCLUSIONS

The OCHL cohort reflects known etiologies of CHH. Despite available guidelines, centers of excellence, and high-yield rates for imaging, the medical workup for children with hearing loss remains inconsistently implemented and widely variable. There remains limited awareness as to what constitutes appropriate medical assessment for CHH.

Utilization of diagnostic testing for pediatric sensorineural hearing loss

BACKGROUND/OBJECTIVE

Sensorineural hearing loss is a common diagnosis among children. The diagnostic workup varies widely among practitioners. This study's aim was to assess the utilization of diagnostic testing for SNHL and determine the yield of each test.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary care center.

SUBJECTS

827 patients with a diagnosis of SNHL from January 1, 2011 to January 1, 2015.

RESULTS

746 patients met inclusion criteria. Temporal bone imaging was performed on 561 (75%) of patients with 224 (40%) having positive results that explained the etiology of the SNHL. Congenital SNHL was more likely to be associated with abnormal imaging than acquired SNHL (109/299 versus 106/316 respectively) (p = 0.001). Unilateral SNHL was more likely to be associated imaging abnormalities than bilateral SNHL (101/221 and 123/340 respectively) (p = 0.028). Genetic testing was performed on 244 (33%) patients, of which 94 (39%) had abnormalities. Positive genetics results were more common with bilateral than unilateral SNHL (82/191 and 12/53 respectively) (p = 0.007). There was no statistically significant difference in the utility of genetic testing for congenital and acquired SNHL (p = 0.0836). Cytomegalovirus (CMV) testing was available for 104 (14%) of patients with 13 (12.5%) being positive and consistent with congenital CMV. Electrocardiogram, urinalysis, and Lyme titers were less useful.

CONCLUSIONS

Imaging and genetic testing had the highest yield in the evaluation of children with SNHL and were the most commonly performed. CMV testing was valuable in neonates who failed newborn hearing screening.

DFNB1 Non-syndromic Hearing Impairment: Diversity of Mutations and Associated Phenotypes

The inner ear is a very complex sensory organ whose development and function depend on finely balanced interactions among diverse cell types. The many different kinds of inner ear supporting cells play the essential roles of providing physical and physiological support to sensory hair cells and of maintaining cochlear homeostasis. Appropriately enough, the gene most commonly mutated among subjects with hereditary hearing impairment (HI), GJB2, encodes the connexin-26 (Cx26) gap-junction channel protein that underlies both intercellular communication among supporting cells and homeostasis of the cochlear fluids, endolymph and perilymph. GJB2 lies at the DFNB1 locus on 13q12. The specific kind of HI associated with this locus is caused by recessively-inherited mutations that inactivate the two alleles of the GJB2 gene, either in homozygous or compound heterozygous states. We describe the many diverse classes of genetic alterations that result in DFNB1 HI, such as large deletions that either destroy the GJB2 gene or remove a regulatory element essential for GJB2 expression, point mutations that interfere with promoter function or splicing, and small insertions or deletions and nucleotide substitutions that target the GJB2 coding sequence. We focus on how these alterations disrupt GJB2 and Cx26 functions and on their different effects on cochlear development and physiology. We finally discuss the diversity of clinical features of DFNB1 HI as regards severity, age of onset, inner ear malformations and vestibular dysfunction, highlighting the areas where future research should be concentrated.

Diagnostic yield of computed tomography scan for pediatric hearing loss: a systematic review

BACKGROUND

Computed tomography (CT) has been used in the assessment of pediatric hearing loss, but concern regarding radiation risk and increased utilization of magnetic resonance imaging (MRI) have prompted us toward a more quantitative and sophisticated understanding of CT's potential diagnostic yield.

OBJECTIVE

To perform a systematic review to analyze the diagnostic yield of CT for pediatric hearing loss, including subgroup evaluation according to impairment severity and laterality, as well as the specific findings of enlarged vestibular aqueduct and narrow cochlear nerve canal.

DATA SOURCES

PubMed, EMBASE, and the Cochrane Library were assessed from the date of their inception to December 2013. In addition, manual searches of bibliographies were performed and topic experts were contacted.

REVIEW METHODS

Data from studies describing the use of CT in the diagnostic evaluation of pediatric patients with hearing loss of unknown etiology were evaluated, according to a priori inclusion/exclusion criteria. Two independent evaluators corroborated the extracted data. Heterogeneity was evaluated according to the I(2) statistic.

RESULTS

In 50 criteria-meeting studies, the overall diagnostic yield of CT ranged from 7% to 74%, with the strongest and aggregate data demonstrating a point estimate of 30%. This estimate corresponded to a number needed to image of 4 (range, 2-15). The most commonly identified findings were enlarged vestibular aqueduct and cochlear anomalies. The largest studies showed a 4% to 7% yield for narrow cochlear nerve canal.

CONCLUSION

These data, along with similar analyses of radiation risk and risks/benefits of sedated MRI, may be used to help guide the choice of diagnostic imaging.

Prevalence of p.V37I variant of GJB2 in mild or moderate hearing loss in a pediatric population and the interpretation of its pathogenicity

A p.V37I variant of GJB2 has been reported from subjects with moderate or slight hearing loss especially in East Asian populations. This study aimed to estimate the prevalence of the p.V37I variant among such subjects and prove, epidemiologically, its pathogenic potential to cause mild hearing loss. A total of 380 subjects from 201 families with hearing loss were enrolled. From them, 103 families were selected who had autosomal recessive inheritance or sporadic occurrence of hearing loss and who were younger than 15 years old. GJB2 sequencing was carried out for the probands of all 103 families. The prevalence of the p.V37I variant was compared between the subtle, mild or moderate hearing loss (group I) and the severe or profound hearing loss (group II) groups. Where possible, a targeted next generation sequencing of 82 deafness genes was performed from the p.V37I carrier to exclude the existence of other pathogenic genes. Five (4.8%) of 103 probands were found to carry p.V37I. The carrier frequency of p.V37I among group I (18.2%) was significantly higher than that of group II (1.2%) or the reported Korean normal hearing control group (1.0%). Detection of the p.V37I variant of GJB2 in 18.2% of Koreans with mild hearing loss strongly suggests its contribution to the pathogenesis of milder hearing loss, which might justify sequencing of GJB2 from these subjects in the Korean population.

Genetics of hearing loss: where are we standing now?

Hearing loss (HL) is the most common sensory impairment and is caused by a broad range of inherited to environmental causes. Inherited HL consists 50-60% of all HL cases. The inherited form of HL is further classified to different categories. More than 300 syndromes and 40 genes have been identified to result in different levels of HL. Although several diagnostic or screening tests have been developed, yet there are controversies around their use.

[Hereditary hearing loss: genetic counselling]

The aim of this review is to provide an updated overview of hereditary hearing loss, with special attention to the etiological diagnosis of sensorineural hearing loss, the genes most frequently mutated in our environment, the techniques available for their analysis and the clinical implications of genetic diagnosis. More than 60% of childhood sensorineural hearing loss is genetic. In adults, the percentage of hereditary hearing loss is unknown. Genetic testing is the highest yielding test for evaluating patients with sensorineural hearing loss. The process of genetic counselling is intended to inform patients and their families of the medical, psychological and familial implications of genetic diseases, as well as the risks, benefits and limitations of genetic testing. The implementation of any genetic analysis must be always preceded by an appropriate genetic counselling process.