Glymphatic System Dysfunction in Congenital Sensorineural Hearing Loss: A DTI-ALPS Study.

BACKGROUND: The neural mechanisms underlying congenital sensorineural hearing loss (CSNHL) remain elusive. OBJECTIVE: This study evaluated the function of the glymphatic system in children with CSNHL compared to normal-hearing children using the DTI-ALPS approach, which utilizes diffusion tensor imaging along the perivascular space. METHODS: Twenty-six children with CSNHL and 30 age- and sex-matched healthy controls (HCs) with normal hearing thresholds were recruited. The DTIALPS index was calculated for each group. We analyzed the discrepancies in the DTI-ALPS index between patients with CSNHL and healthy controls. Additionally, Spearman's correlation analysis was performed to investigate the relationship between the DTI-ALPS index and age in children with CSNHL. RESULTS: Significant differences in the DTI-ALPS index were observed between the two groups. Compared with HCs, the DTI-ALPS index in CSNHL patients was significantly lower (1.49388±0.11441 vs. 1.61402±0.15430, p=0.002). In addition, diffusivity along the z-axis in the association fiber (Dzzassoc) index was significantly higher in the CSNHL group than in the HC group (0.00041±0.00006 vs. 0.00036±0.00004, p=0.003). Furthermore, we discovered a noteworthy downward correlation between the DTI-ALPS index and age in children with CSNHL (rho = -0.544, p=0.005). CONCLUSION: In this present study, glymphatic system activity in CSNHL children was investigated for the first time using the DTI-ALPS index. A significant decrease in glymphatic system function was detected in CSNHL children, which correlated well with age. The DTI-ALPS index could serve as a valuable biomarker for tracking disease progression and treatment in CSNHL and unraveling the neural mechanisms of early hearing deprivation in children with CSNHL.

Cerebral cortex functional reorganization in preschool children with congenital sensorineural hearing loss: a resting-state fMRI study.

Purpose: How cortical functional reorganization occurs after hearing loss in preschool children with congenital sensorineural hearing loss (CSNHL) is poorly understood. Therefore, we used resting-state functional MRI (rs-fMRI) to explore the characteristics of cortical reorganization in these patents. Methods: Sixty-three preschool children with CSNHL and 32 healthy controls (HCs) were recruited, and the Categories of Auditory Performance (CAP) scores were determined at the 6-month follow-up after cochlear implantation (CI). First, rs-fMRI data were preprocessed, and amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo) were calculated. Second, whole-brain functional connectivity (FC) analysis was performed using bilateral primary auditory cortex as seed points. Finally, Spearman correlation analysis was performed between the differential ALFF, ReHo and FC values and the CAP score. Results: ALFF analysis showed that preschool children with CSNHL had lower ALFF values in the bilateral prefrontal cortex and superior temporal gyrus than HCs, but higher ALFF values in the bilateral thalamus and calcarine gyrus. And correlation analysis showed that some abnormal brain regions were weak negatively correlated with CAP score (p < 0.05). The ReHo values in the bilateral superior temporal gyrus, part of the prefrontal cortex and left insular gyrus were lower, whereas ReHo values in the bilateral thalamus, right caudate nucleus and right precentral gyrus were higher, in children with CSNHL than HCs. However, there was no correlation between ReHo values and the CAP scores (p < 0.05). Using primary auditory cortex (PAC) as seed-based FC further analysis revealed enhanced FC in the visual cortex, proprioceptive cortex and motor cortex. And there were weak negative correlations between the FC values in the bilateral superior temporal gyrus, occipital lobe, left postcentral gyrus and right thalamus were weakly negatively correlated and the CAP score (p < 0.05). Conclusion: After auditory deprivation in preschool children with CSNHL, the local functions of auditory cortex, visual cortex, prefrontal cortex and somatic motor cortex are changed, and the prefrontal cortex plays a regulatory role in this process. There is functional reorganization or compensation between children's hearing and these areas, which may not be conducive to auditory language recovery after CI in deaf children.

Nomogram for prediction of hearing rehabilitation outcome in children with congenital sensorineural hearing loss after cochlear implantation.

Background: Reliable predictors for rehabilitation outcomes in patients with congenital sensorineural hearing loss (CSNHL) after cochlear implantation (CI) are lacking. The purchase of this study was to develop a nomogram based on clinical characteristics and neuroimaging features to predict the outcome in children with CSNHL after CI. Methods: Children with CSNHL prior to CI surgery and children with normal hearing were enrolled into the study. Clinical data, high resolution computed tomography (HRCT) for ototemporal bone, conventional brain MRI for structural analysis and brain resting-state fMRI (rs-fMRI) for the power spectrum assessment were assessed. A nomogram combining both clinical and imaging data was constructed using multivariate logistic regression analysis. Model performance was evaluated and validated using bootstrap resampling. Results: The final cohort consisted of 72 children with CSNHL (41 children with poor outcome and 31 children with good outcome) and 32 healthy controls. The white matter lesion from structural assessment and six power spectrum parameters from rs-fMRI, including Power4, Power13, Power14, Power19, Power23 and Power25 were used to build the nomogram. The area under the receiver operating characteristic (ROC) curve of the nomogram obtained using the bootstrapping method was 0.812 (95 % CI = 0.772-0.836). The calibration curve showed no statistical difference between the predicted value and the actual value, indicating a robust performance of the nomogram. The clinical decision analysis curve showed a high clinical value of this model. Conclusions: The nomogram constructed with clinical data, and neuroimaging features encompassing ototemporal bone measurements, white matter lesion values from structural brain MRI and power spectrum data from rs-fMRI showed a robust performance in predicting outcome of hearing rehabilitation in children with CSNHL after CI.

Clinical Presentation of Usher Syndrome Type 1B (USH1B) in a 10-Month-Old: A Case Report.

Usher Syndrome (USH) is a genetically inherited condition characterized by congenital sensorineural hearing loss and progressive vision loss secondary to retinitis pigmentosa. Patients may also display vestibular areflexia and balance issues secondary to inner ear damage. Usher Syndrome is the most commonly diagnosed syndrome within the blind-deaf community, and it accounts for a significant portion of the hearing and visual deficit cases among patients younger than 65 years of age. Due to the reported prevalence of Usher Syndrome in the United States, it appears there is chronic underdiagnosis in clinical settings throughout the country. A possible explanation for this is the visual deficits of Usher syndrome do not appear until later in life and thus inappropriately lower the index of suspicion for this diagnosis in young children with hearing deficits. This case study highlights a healthy newborn who failed the universal newborn hearing screening (UNHS) bilaterally and a follow-up hearing screening in a pediatrician's office. Auditory brainstem response (ABR) later confirmed bilateral severe-to-profound sensorineural hearing loss. Upon genetic testing, an abnormality in the Unconventional Myosin VII-A (MYO7) gene was discovered and consistent with Usher syndrome Type 1B (USH1B). Usher Syndrome should be considered on the differential for patients with congenital hearing loss. Genetic counseling should be used if no other cause of sensorineural hearing loss is identified. Due to the progressive nature of this condition and the physical and developmental deficits that will transpire without treatment, a genetic panel for hearing loss should be prioritized to determine the presence of genetic mutations suggesting Usher syndrome.

Long-term outcome of patients with alpha-mannosidosis - A single center study.

INTRODUCTION: Alpha-mannosidosis (AM) is a rare autosomal recessive lysosomal storage disease which the natural history has not been exhaustively described yet. The aim of this study was to present the long-term follow-up of 12 Polish patients with AM, evaluate the clinical, biochemical, and molecular findings and progression of the disease. MATERIAL AND METHODS: The article presents a long-term (over 30 years) observational, retrospective, single-center study of patients with AM. RESULTS: The hearing loss, as one of the first symptoms, was detected in childhood (mean age of 2 years and 6 months) in 10 patients. The other symptoms include: recurrent infections (all patients), inguinal hernias (6 patients), craniosynostosis (1 patient). The mean age at AM diagnosis was 6 years while median was 4 years (age range: 1 year and 8 months - 12 years). The most commonly identified variant in the MAN2B1 gene was c.2245C > T, p.(Arg749Trp). The mean time of follow-up in our study was approximately 14 years (range: 1 year - 26 years). Following birth, children with AM grow slowly, finally reaching the 3rd percentile (or values below the 3rd percentile). Hearing loss was not progressive while a gradual exacerbation of intellectual disability with no developmental regression was observed in all patients. Ataxia was diagnosed in 6 patients in the second decade of life (age range 15-20 years). CONCLUSIONS: Our study revealed the sensorineural hearing loss as one of the first noted symptom in AM which was congenital and non-progressive during the natural course of disease. A detailed anthropometric phenotype of AM patients was provided with observation of the growth decline during the long-term follow-up. Our study confirmed the existence of two distinguished clinical phenotypes of AM (mild and moderate), and also the lack of clear genotype-phenotype correlation.

The genes for sensory perception of sound should be considered in gene diagnosis of congenital sensorineural hearing loss and microtia.

Congenital sensorineural hearing loss (CSHL) and microtia are development-related diseases, sharing some factors and affecting children's hearing. However, genetic tests only focus on CSHL. We try to identify the common molecular mechanism of CSHL and microtia as candidates combining gene diagnosis biomarkers. Whole-exon sequencing (WES), Sanger sequencing, qPCR, and bioinformatics analyses were performed in microtia family (F1), family two, whose proband suffered from microtia and CSHL (F2), five microtia, and four CSHL individuals, respectively. We found that 40% microtia and 40% CSHL relevant genes were detected in F1 and a sharing pathway: the sensory perception of sound was identified. Moreover, the copy number variation in proband F2 was identified in one gene of the sharing pathway: EYA1. Meanwhile, two variants of BUB3 were identified in F1 data. BUB3 is related to development, dog ear type, direct and indirect interaction with microtia, and CSHL relevant genes. Notably, although the allele frequency of two variants of BUB3 showed significant differences between microtia and CSHL, the special microtia-relevant genotype also could be detected in one CSHL sample. These results suggest that the sensory perception of sound and the development of relevant pathways may be the common pathways of microtia and CSHL. Genes of these pathways can be used as candidates combining gene diagnosis biomarkers.

Alterations of Regional Homogeneity in Children With Congenital Sensorineural Hearing Loss: A Resting-State fMRI Study.

Background: Brain functional alterations have been observed in children with congenital sensorineural hearing loss (CSNHL). The purpose of this study was to assess the alterations of regional homogeneity in children with CSNHL. Methods: Forty-five children with CSNHL and 20 healthy controls were enrolled into this study. Brain resting-state functional MRI (rs-fMRI) for regional homogeneity including the Kendall coefficient consistency (KCC-ReHo) and the coherence-based parameter (Cohe-ReHo) was analyzed and compared between the two groups, i.e., the CSNHL group and the healthy control group. Results: Compared to the healthy controls, children with CSNHL showed increased Cohe-ReHo values in left calcarine and decreased values in bilateral ventrolateral prefrontal cortex (VLPFC) and right dorsolateral prefrontal cortex (DLPFC). Children with CSNHL also had increased KCC-ReHo values in the left calcarine, cuneus, precentral gyrus, and right superior parietal lobule (SPL) and decreased values in the left VLPFC and right DLPFC. Correlations were detected between the ReHo values and age of the children with CSNHL. There were positive correlations between ReHo values in the pre-cuneus/pre-frontal cortex and age (p < 0.05). There were negative correlations between ReHo values in bilateral temporal lobes, fusiform gyrus, parahippocampal gyrus and precentral gyrus, and age (p < 0.05). Conclusion: Children with CSNHL had RoHo alterations in the auditory, visual, motor, and other related brain cortices as compared to the healthy controls with normal hearing. There were significant correlations between ReHo values and age in brain regions involved in information integration and processing. Our study showed promising data using rs-fMRI ReHo parameters to assess brain functional alterations in children with CSNHL.

Phosphatidylinositol 4-kinase ß mutations cause nonsyndromic sensorineural deafness and inner ear malformation.

Congenital hearing loss is a common disorder worldwide. Heterogeneous gene variation accounts for approximately 20-25% of such patients. We investigated a five-generation Chinese family with autosomal-dominant nonsyndromic sensorineural hearing loss (SNHL). No wave was detected in the pure-tone audiometry, and the auditory brainstem response was absent in all patients. Computed tomography of the patients, as well as of two sporadic SNHL cases, showed bilateral inner ear anomaly, cochlear maldevelopment, absence of the osseous spiral lamina, and an enlarged vestibular aqueduct. Such findings were absent in nonaffected persons. We used linkage analysis and exome sequencing and uncovered a heterozygous missense mutation in the PI4KB gene (p.Gln121Arg) encoding phosphatidylinositol 4-kinase ß (PI4KB) from the patients in this family. In addition, 3 missense PI4KB (p.Val434Gly, p.Glu667Lys, and p.Met739Arg) mutations were identified in five patients with nonsyndromic SNHL from 57 sporadic cases. No such mutations were present within 600 Chinese controls, the 1000 genome project, gnomAD, or similar databases. Depleting pi4kb mRNA expression in zebrafish caused inner ear abnormalities and audiosensory impairment, mimicking the patient phenotypes. Moreover, overexpression of 4 human missense PI4KB mutant mRNAs in zebrafish embryos resulted in impaired hearing function, suggesting dominant-negative effects. Taken together, our results reveal that PI4KB mutations can cause SNHL and inner ear malformation. PI4KB should be included in neonatal deafness screening.

Assessing Cerebral White Matter Microstructure in Children With Congenital Sensorineural Hearing Loss: A Tract-Based Spatial Statistics Study.

OBJECTIVES: To assess the microstructural properties of cerebral white matter in children with congenital sensorineural hearing loss (CSNHL). METHODS: Children (>4 years of age) with profound CSNHL and healthy controls with normal hearing (the control group) were enrolled and underwent brain magnetic resonance imaging (MRI) scans with diffusion tensor imaging (DTI). DTI parameters including fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity were obtained from a whole-brain tract-based spatial statistics analysis and were compared between the two groups. In addition, a region of interest (ROI) approach focusing on auditory cortex, i.e., Heschl's gyrus, using visual cortex, i.e., forceps major as an internal control, was performed. Correlations between mean DTI values and age were obtained with the ROI method. RESULTS: The study cohort consisted of 23 children with CSHNL (11 boys and 12 girls; mean age ± SD: 7.21 ± 2.67 years; range: 4.1-13.5 years) and 18 children in the control group (11 boys and 7 girls; mean age ± SD: 10.86 ± 3.56 years; range: 4.5-15.3 years). We found the axial diffusivity values being significantly greater in the left anterior thalamic radiation, right corticospinal tract, and corpus callosum in the CSHNL group than in the control group (p < 0.05). Significantly higher radial diffusivity values in the white matter tracts were noted in the CSHNL group as compared to the control group (p < 0.05). The fractional anisotropy values in the Heschl's gyrus in the CSNHL group were lower compared to the control group (p = 0.0015). There was significant negative correlation between the mean fractional anisotropy values in Heschl's gyrus and age in the CSNHL group < 7 years of age (r = -0.59, p = 0.004). CONCLUSION: Our study showed higher axial and radial diffusivities in the children affected by CNHNL as compared to the hearing children. We also found lower fractional anisotropy values in the Heschl's gyrus in the CSNHL group. Furthermore, we identified negative correlation between the fractional anisotropy values and age up to 7 years in the children born deaf. Our study findings suggest that myelination and axonal structure may be affected due to acoustic deprivation. This information may help to monitor hearing rehabilitation in the deaf children.

DTI study on rehabilitation of the congenital deafness auditory pathway and speech center by cochlear implantation.

PURPOSE: To explore the correlation between hearing and speech recovery levels after cochlear implantation and examined the preoperative microstructure of auditory pathways and speech centre using DTI. METHODS: (1) Fifty-two SNHL children between 0 and 6 years and 19 age and gender matched normal hearing subjects had received 3.0 T-MRI examination of the brain.FA, axial diffusion coefficient (λ‖), radial diffusion coefficient (λ⊥), and MD values in the lateral lemniscus, inferior colliculus, medial geniculate bodies, auditory radiations, Brodmann areas 41, 42, 22, 44, 45, and 39 were all measured bilaterally. (2) CAP and SIR scores were assessed in fourty-six cochlear implantation children at 6 months post-implant. Correlations among deaf children ages, FA value of bilateral inferior colliculus FA values, BA22, BA44, and postoperative CAP, and SIR scores were analyzed using multiple linear regression. RESULTS: The preoperative standard partial regression age coefficient of deaf children (|bi'| = 0.404) was slightly greater than that of the inferior colliculus (|bi'| = 0.377) FA value. CONCLUSION: Preoperative children ages and inferior colliculus FA values were important factors influencing postoperative CAP score. Inferior colliculus FA value is a vital influencing factor in rehabilitation after cochlear implantation.

Is PNPT1-related hearing loss ever non-syndromic? Whole exome sequencing of adult siblings expands the natural history of PNPT1-related disorders.

PNPT1 is a mitochondrial RNA transport protein that has been linked to two discrete phenotypes, namely isolated sensorineural hearing loss (OMIM 614934) and combined oxidative phosphorylation deficiency (OMIM 614932). The latter has been described in multiple families presenting with complex neurologic manifestations in childhood. We describe adult siblings with biallelic PNPT1 variants identified through WES who presented with isolated severe congenital sensorineural hearing loss (SNHL). In their 40s, they each developed and then followed a nearly identical neurodegenerative course with ataxia, dystonia, and cognitive decline. Now in their 50s and 60s, all have developed the additional features of optic nerve atrophy, spasticity, and incontinence. The natural history of the condition in this family may suggest that the individuals previously reported as having isolated SNHL may be at risk of developing multisystem disease in late adulthood, and that PNPT1-related disorders may constitute a spectrum rather than distinct phenotypes.

High prevalence of abnormalities on CT and MR imaging in children with unilateral sensorineural hearing loss irrespective of age or degree of hearing loss.

OBJECTIVE: Evaluation of causal abnormalities identified on CT and MR imaging in children with unilateral sensorineural hearing loss (USNHL), and the association with age and severity of hearing loss. STUDY DESIGN: Retrospective cohort study. SETTING: Tertiary referral otology/audiology center. PATIENTS AND DIAGNOSTIC INTERVENTIONS: 102 children diagnosed with USNHL between 2006 and 2016 were included. They underwent CT and/or MR imaging for the evaluation of the etiology of their hearing loss. MAIN OUTCOME MEASURES: Radiologic abnormalities of the inner ear and brain associated with USNHL. RESULTS: Using CT and/or MR imaging, causal abnormalities were identified in 49%, which is higher than previously reported (25-40%). The most frequently affected site was the labyrinth (29%), followed by the cochlear nerve (9%) and brain (7%). No significant difference in the number or type of abnormalities was found for the degree of hearing loss or age categories. CONCLUSIONS: Imaging is essential in the etiologic analysis of USNHL because of the high prevalence of causative abnormalities that can be identified with radiology, irrespective of the patients' age or degree of hearing loss. CT and MR imaging are complementary imaging options. The ideal imaging algorithm is controversial. Based on our findings, we conclude that there is limited additional diagnostic value of simultaneous dual modality imaging over sequential diagnostics. We therefore perform a stepwise radiological workup in order to maximize the diagnostic yield while minimizing impact and costs. If the primary imaging modality does not identify a cause for USNHL, performing the alternative imaging modality should be considered. LEVEL OF EVIDENCE: Retrospective cohort study 2b.

The new classification system for inner ear malformations: the INCAV system.

CONCLUSIONS: The proposed INCAV system standardizes reporting of inner ear malformations; gives adequate information about the structures of inner ear; defines the ears which could not be classified before; and helps in the selection of the ear as the cochlear implant candidate. Also it is easy-to-use for radiologists, and useful to the referring otolaryngologists. OBJECTIVE: This study was conducted to explore a more specific, definitive classification system which was based on radiological criteria for inner ear malformations. METHOD: This study found 43 patients who had inner ear malformations, magnetic resonance (MR), and computed tomography (CT) imaging, together with the retrospective evaluation of the medical records between August 2010 and February 2015. It analyzed inner ear structures by dividing five sub-groups and each sub-group was given a letter: internal acoustic canal (I), cochlear nerve (N), cochlea (C), vestibular aqueduct (A) and vestibule (V). Based on their malformations, these anatomical structures have been assigned grades and have been classified by using increasing numbers which were dependent to increasing order of severity of the malformation. RESULTS: Among these 43 patients, there were six normal (I0N0C0A0V0) and 80 inner ear malformations. All of the ears were defined successfully by the INCAV system.

Diffusion tensor imaging and MR spectroscopy of microstructural alterations and metabolite concentration changes in the auditory neural pathway of pediatric congenital sensorineural hearing loss patients.

PURPOSE: Our objective was to evaluate age-dependent changes in microstructure and metabolism in the auditory neural pathway, of children with profound sensorineural hearing loss (SNHL), and to differentiate between good and poor surgical outcome cochlear implantation (CI) patients by using diffusion tensor imaging (DTI) and magnetic resonance spectroscopy (MRS). MATERIALS AND METHODS: Ninety-two SNHL children (49 males, 43 females; mean age, 4.9 years) were studied by conventional MR imaging, DTI and MRS. Patients were divided into three groups: Group A consisted of children≤1 years old (n=20), Group B consisted of children 1-3 years old (n=31), and group C consisted of children 3-14 years old (n=41). Among the 31 patients (19 males and 12 females, 12m- 14y ) with CI, 18 patients (mean age 4.8±0.7 years) with a categories of auditory performance (CAP) score over five were classified into the good outcome group and 13 patients (mean age, 4.4±0.7 years) with a CAP score below five were classified into the poor outcome group. Two DTI parameters, fractional anisotropy (FA) and apparent diffusion coefficient (ADC), were measured in the superior temporal gyrus (STG) and auditory radiation. Regions of interest for metabolic change measurements were located inside the STG. DTI values were measured based on region-of-interest analysis and MRS values for correlation analysis with CAP scores. RESULTS: Compared with healthy individuals, 92 SNHL patients displayed decreased FA values in the auditory radiation and STG (p<0.05). Only decreased FA values in the auditory radiation was observed in Group A. Decreased FA values in the auditory radiation and STG were both observed in B and C groups. However, in Group C, the N-acetyl aspartate/creatinine ratio in the STG was also significantly decreased (p<0.05). Correlation analyses at 12 months post-operation revealed strong correlations between the FA, in the auditory radiation, and CAP scores (r=0.793, p<0.01). CONCLUSIONS: DTI and MRS can be used to evaluate microstructural alterations and metabolite concentration changes in the auditory neural pathway that are not detectable by conventional MR imaging. The observed changes in FA suggest that children with SNHL have a developmental delay in myelination in the auditory neural pathway, and it also display greater metabolite concentration changes in the auditory cortex in older children, suggest that early cochlear implantation might be more effective in restoring hearing in children with SNHL. This article is part of a Special Issue entitled SI: Brain and Memory.

Evaluación de mutaciones en los genes GJB2 y GJB6 en pacientes con sordera congénita identificados mediante screening neonatal / Evaluation of GJB2 and GJB6 gene mutation in Chilean patients with congenital deafness identified through neonatal screening

If not detected and treated early, congenital sensorineural hearing loss generates impairment in linguistic, intellectual and social development of individuals. Most congenital hearing deficits are genetic. The most common causes are mutations in GJB2 and GJB6 genes, both located on chromosome 13, encoding junction proteins that allow the transduction of sound in the inner ear. Objetive: To evaluate the presence of mutations in GJB2 and GJB6 genes in a population of children diagnosed with deafness in Complejo Hospitalario Sótero del Río since implementation of the universal newborn hearing screening program. Patients and Methods: 8 patients with congenital nonsyndromic sensorineural deafness were evaluated. Genomic DNA was extracted from oral mucosa swabs. PCR was performed to identify the 35 del G mutation in GJB2, followed by sequencing of this gene, and PCR for 2 GJB6 deletions. Results: Two patients were heterozygous for 35 del G mutation in GJB2, being their other alleles normal. Another 2 patients were heterozygous for V27I polymorphism, one of them also accompanied by p.A148A (c.444C > A) variant. A patient was found with a previously undescribed mutation (c.4360 C>T) in GJB2's intron 1, being the second allele normal. No mutations were identified in GJB6. Conclusions: In this population of children, mutations in the GJB2 gene were an identifiable cause of congenital sensorineural.

La hipoacusia neurosensorial congénita es una patología frecuente que si no es detectada y tratada oportunamente genera alteraciones en el desarrollo del niño. Desde el año 2005 se lleva a cabo en el Complejo Hospitalario Dr. Sótero del Río un programa de screening auditivo universal para la detección precoz de esta patología. La mayor parte de los déficits auditivos congénitos son genéticos. La etiología más común son las mutaciones en los genes GJB2 y GJB6, que codifican para proteínas "gap junction" que permiten la traducción del sonido en el oído interno. Objetivo: Evaluar la presencia de mutaciones de los genes GJB2 y GJB6 en una población de niños diagnosticados con hipoacusia congénita en el Complejo Hospitalario Dr. Sótero del Río a través del programa de screening auditivo universal. Pacientes y Método: Se evaluaron 8 pacientes con hipoacusia congénita neurosensorial no sindrómica. Se extrajo ADN genómico de hisopado de mucosa bucal y se realizó PCR para identificar la mutación 35 del G en GJB2, seguida de secuenciación de este gen, y PCR para 2 deleciones del gen GJB6. Resultados: Dos pacientes fueron heterocigotos para la mutación 35 del G en GJB2, siendo sus otros alelos normales. Dos fueron heterocigotos para el polimorfismo V27I; uno acompañado por la variante p.A148A (c.444 C > A). Se encontró además un paciente con una mutación no descrita anteriormente (c.4360 C>T) en el intrón 1 de GJB2, siendo su segundo alelo normal. No se identificaron mutaciones en GJB6. Conclusiones: En este grupo de niños estudiados se encontró mutaciones en el gen GJB2, causantes de sordera neurosensorial congénita.