A rare case of deafness and renal abnormalities in HDR syndrome caused by a de novo mutation in the GATA3 gene.

HDR syndrome is a rare autosomal dominant disorder caused by mutations in the GATA3 gene and characterized by hypoparathyroidism, sensorineural deafness and renal abnormalities. Here we report a Brazilian family, from which the proband, his mother and his grandfather were diagnosed with bilateral sensorineural hearing loss. Molecular screening of the GJB2, GJB6 and MTRNR1 genes in the proband showed no alterations; however, whole exome sequencing detected a heterozygous mutation, c.1099C > T (p.Arg367*), in the GATA3 gene. Segregation analyses showed that the mother also had the mutation, but not the grandparents, hence indicating a different hearing impairment type for the grandfather. Paternity test of the mother of the proband confirmed that she has a de novo mutation. Furthermore, HDR syndrome was confirmed with new clinical evaluations showing right kidney agenesis in the proband. This is the first study reporting only deafness and renal abnormalities as symptoms of the p.Arg367* mutation in the GATA3 gene, and also the sixth HDR syndrome case in the world, and the first on the American continent. Together with other reported cases, this study highlights the variability of HDR syndrome symptoms in individuals with the p.Arg367* mutation, emphasizing the importance of molecular analyses for correct diagnosis.

Optimization of a genotyping screening based on hydrolysis probes to detect the main mutations related to Leber hereditary optic neuropathy (LHON).

PURPOSE: Leber hereditary optic neuropathy (LHON) is a mitochondrial inherited disease characterized by bilateral vision problems, such as reduced visual acuity, dyschromatopsia, and central or centrocecal scotoma. Of these cases, 95% are caused by three mutations in mitochondrial DNA (mtDNA): m.G11778A, followed by m.T14484C and m.G3460A. The remaining 5% of cases of LHON are caused by rare mutations also present in mtDNA. Although conventional molecular tools for molecular screening of LHON are becoming popular, in most cases these tools are still expensive and time-consuming and are difficult to reproduce. Therefore, to meet the need for more accurate, faster, and cheaper techniques for molecular screening, as well as make it more accessible, we used the high-throughput method TaqMan® OpenArray™ Genotyping platform for developing a customized high-throughput assay for the three main mutations related to LHON. METHODS: The assay was performed for 87 individuals diagnosed with LHON or acquired optic neuropathy of unknown origin. The three main mutations were screened using the customized assay with the TaqMan® OpenArray™ Genotyping platform, and all reactions were performed in triplicate. The positive and negative results were revalidated with restriction fragment length polymorphism PCR (RFLP-PCR) and Sanger sequencing. RESULTS: The main mutations related to LHON were detected in 34 patients with genotyping reactions, of which 27 cases had the m.G11778A mutation, and seven had the m.T14484C mutation. CONCLUSIONS: The TaqMan® OpenArray™ Genotyping platform was shown to be an effective tool for molecular screening of the most common mutations related to LHON without presenting false positive or negative results for the analyzed mutations. In addition, this tool can be considered a cheaper, faster, and more accurate alternative for molecular screening of LHON mutations than PCR and Sanger sequencing, as 94 genotyping reactions can be performed within 6 h and specific TaqMan probes are used.

Differentiating Leber Hereditary Optic Neuropathy from Normal-Tension Glaucoma.

Glaucoma is a neurodegenerative disorder characterized by thinning of neuroretinal rim, enlarged cup-to-disc ratio (CDR) and visual field damage. Although raised intraocular pressure is main risk factor for development of glaucoma, it can occur with consistently normal measurements in the intraocular pressure as normal tension glaucoma (NTG). Enlargement of CDR is a classical sign of glaucoma, but it can also result from non-glaucomatous optic neuropathies such as Leber hereditary optic neuropathy (LHON). We describe a case of LHON with increased CDR, discuss its differential diagnosis with NTG and highlight the reasons for misdiagnoses between these two entities.

[Auditory Neuropathy: Clinical Evaluation and Diagnostic Approach]. / Neuropatia Auditiva: Avaliação Clínica e Abordagem Diagnóstica.

INTRODUCTION: Auditory neuropathy is a condition in which there is a change in the neuronal transmission of the auditory stimuli. Our objective was to describe the patients' series within the clinical spectrum of auditory neuropathy. MATERIAL AND METHODS: We designed a transversal, retrospective study, with a description of a consecutive case series. Auditory neuropathy was defined by the presence of acoustic otoemissions plus absent/abnormal auditory brainstem responses with cochlear microphonism. RESULTS: 34 patients with bilateral hearing loss, 23 males and 11 females, were included in the study. Eighty percent of the cases had congenital onset of hearing loss. Acoustic otoemissions were absent in 67% of them. Cochlear microfonism was present in 79% of all cases. Prenatal, perinatal or ambiental factors were present in 35.2% of the cases. DISCUSSION: Medical literature shows great variability in findings related to auditory neuropathy, both in its etiology and epidemiological data. CONCLUSION: Auditory neuropathy presents a broad spectrum of changes that may result from mild to severe changes in the functioning of the auditory pathway, and in our sample we observed that 80% of Auditory neuropathy have congenital onset of hearing loss and/or with cochlear microphonism identified. 91% of patients experience significant hearing impairment and 53% suffer from severe or profound deafness.

Introdução: A neuropatia auditiva é uma condição na qual há alteração na condução neuronal do estímulo sonoro. Este trabalho pretende descrever e caracterizar a casuística de doentes com neuropatia auditiva. Material e Métodos: Realizámos um estudo transversal, retrospetivo, com descrição de uma série de casos consecutivos. O diagnóstico da neuropatia auditiva foi definido nas seguintes situações: Presença de otoemissões acústicas com potenciais auditivos de tronco encefálico ausente ou anormal e presença do microfonismo coclear independentemente da presença de otoemissões acústicas. Resultados: Foram avaliados 34 doentes com perda auditiva bilateral, 67% deles do sexo masculino. O aparecimento dos sintomas foi congênito em 80% dos casos. Na pesquisa das otoemissões acústicas, a resposta foi ausente em 67% dos doentes. O microfonismo coclear foi detetado em 79% dos doentes. Antecedentes gestacionais, perinatais ou ambientais relevantes estiveram presentes em 35,3% dos casos. Discussão: A literatura médica ainda apresenta grande variabilidade nos achados relacionados com a neuropatia auditiva, tanto na sua etiologia quanto nos dados epidemiológicos. Conclusão: A neuropatia auditiva apresenta um amplo espectro de alterações que podem resultar em disfunções leves a severas no funcionamento da via auditiva. Na nossa amostra, observámos que 80% das neuropatias auditivas terão tido origem congênita e/ou apresenta microfonismo coclear, 91% dos doentes apresenta défice auditivo significativo e 53% sofrem de surdez severa ou profunda.

Multiplex MALDI-TOF MS detection of mitochondrial variants in Brazilian patients with hereditary optic neuropathy.

PURPOSE: Leber hereditary optic neuropathy (LHON) is a mitochondrial disease characterized by bilateral vision loss. More than 95% of LHON cases are associated with one of the three main mtDNA mutations: G11778A, T14484C, and G3460A. The other 5% of cases are due to other rare mutations related to the disease. The aim of this study was to identify the prevalence and spectrum of LHON mtDNA mutations, including the haplogroup, in a cohort of Brazilian patients with optic neuropathy and to evaluate the usefulness of iPLEX Gold/matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) technology in detecting LHON mutations. METHODS: We analyzed a total of 101 patients; 67 had a clinical diagnosis of LHON and 34 had optic neuropathy of unknown etiology. Direct sequencing and iPLEX Gold/MALDI-TOF MS were used to screen for the most common pathogenic point mutations in LHON, together with the rare mutations G3733A, C4171A, T10663C, G14459A, C14482G, A14495G, C14568T, and C14482A. RESULTS: We identified mutations in 36 patients, of whom 83.3% carried the G11778A mutation and 16.7% carried the T14484C mutation. In individuals with mutations, the haplogroups found were L1/L2, L3, C, R, U, D, and H. Rare mutations were not detected in any of the patients analyzed. CONCLUSIONS: The frequencies of the main LHON mutations were similar to those previously reported for Latin America. A different frequency was found only for the A3460G mutation. The most frequent haplogroups identified were of African origin. The iPLEX Gold/MALDI-TOF MS technology proved to be highly accurate and efficient for screening mutations and identifying the haplogroups related to LHON. The MassArray platform, combined with other techniques, enabled definitive diagnosis of LHON in 36% (36/101) of the cases studied.

Ménière's Disease: Molecular Analysis of Aquaporins 2, 3 and Potassium Channel KCNE1 Genes in Brazilian Patients.

OBJECTIVES: Ménière's disease (MD) is a complex disease of unknown etiology characterized by a symptomatic tetrad of vertigo, hearing loss, tinnitus, and aural fullness. In addition to factors related to homeostasis of the inner ear, genetic factors have been implicated in its pathophysiology, including genes related to the transport of water and ionic composition maintenance of the endolymph, such as the aquaporin genes AQP2 and AQP3, and the potassium channel gene KCNE1. The aim of this study was to identify polymorphisms of these genes and determine their association with clinical characteristics of patients with MD. DESIGN: A case-control genetic association study was carried out, including 30 patients with definite Ménière's disease and 30 healthy controls. The coding regions of the target genes were amplified from blood samples by polymerase chain reaction (PCR), followed by direct sequencing. The associations of polymorphisms with clinical characteristics were analyzed with logistic regression. RESULTS: Five polymorphisms were identified: rs426496 in AQP2; rs591810 in AQP3; and rs1805127, rs1805128, and rs17173510 in KCNE1. After adjustment, rs426496 was significantly associated with tinnitus during the initial crisis and with altered electronystagmography, and rs1805127 was significantly associated with nephropathy. CONCLUSIONS: The genetic variant rs426496 in AQP2; rs591810 in AQP3 and rs1805127, rs1805128, and rs17173510, in KCNE1 were found in patients with Ménière's disease. The polymorphism rs426496, in AQP2, is associated with tinnitus at the onset of Ménière's disease and altered electronystagmography. In addition, rs1805127, in KCNE1, is associated with the presence of nephropathy.

Molecular study of patients with auditory neuropathy.

Auditory neuropathy is a type of hearing loss that constitutes a change in the conduct of the auditory stimulus by the involvement of inner hair cells or auditory nerve synapses. It is characterized by the absence or alteration of waves in the examination of brainstem auditory evoked potentials, with otoacoustic and/or cochlear microphonic issues. At present, four loci associated with non­syndromic auditory neuropathy have been mapped: Autosomal recessive deafness­9 [DFNB9; the otoferlin (OTOF) gene] and autosomal recessive deafness­59 [DFNB59; the pejvakin (PJVK) gene], associated with autosomal recessive inheritance; the autosomal dominant auditory neuropathy gene [AUNA1; the diaphanous­3 (DIAPH3) gene]; and AUNX1, linked to chromosome X. Furthermore, mutations of connexin 26 [the gap junction ß2 (GJB2) gene] have also been associated with the disease. OTOF gene mutations exert a significant role in auditory neuropathy. In excess of 80 pathogenic mutations have been identified in individuals with non­syndromic deafness in populations of different origins, with an emphasis on the p.Q829X mutation, which was found in ~3% of cases of deafness in the Spanish population. The identification of genetic alterations responsible for auditory neuropathy is one of the challenges contributing to understand the molecular bases of the different phenotypes of hearing loss. Thus, the present study aimed to investigate molecular changes in the OTOF gene in patients with auditory neuropathy, and to develop a DNA chip for the molecular diagnosis of auditory neuropathy using mass spectrometry for genotyping. Genetic alterations were investigated in 47 patients with hearing loss and clinical diagnosis of auditory neuropathy, and the c.35delG mutation in the GJB2 gene was identified in three homozygous patients, and the heterozygous parents of one of these cases. Additionally, OTOF gene mutations were tracked by complete sequencing of 48 exons, although these results are still preliminary. Studying the genetic basis of auditory neuropathy is of utmost importance for obtaining a differential diagnosis, developing more specific treatments and more accurate genetic counseling.

Analysis of mitochondrial alterations in Brazilian patients with sensorineural hearing loss using MALDI-TOF mass spectrometry.

BACKGROUND: Mutations in the mitochondrial DNA (mtDNA) have been associated with aminoglycoside-induced and nonsyndromic deafness in different populations. In the present study, we investigated the contribution of mutations in mitochondrial genes to the etiology of hearing loss in a Brazilian sample. METHODS: Using mass spectrometry genotyping technology, combined with direct sequencing, 50 alterations previously described in 14 mitochondrial genes were screened in 152 patients with sensorineural hearing loss and in104 normal hearing controls. RESULTS: Fifteen known mitochondrial alterations were detected (G709A, A735G, A827G, G988A, A1555G, T4363C, T5628C, T5655C, G5821A, C7462T, G8363A, T10454C, G12236A, T1291C, G15927A). Pathogenic mutations in MT-RNR1 and MT-TK genes were detected in 3 % (5/152) of the patients with hearing loss. CONCLUSIONS: This study contributed to show the spectrum of mitochondrial variants in Brazilian patients with hearing loss. Frequency of A1555G was relatively high (2.6 %), indicating that this mutation is an important cause of hearing loss in our population. This work reports for the first time the investigation and the detection of the tRNA(Lys) G8363A mutation in Brazilian patients with maternally inherited sensorineural hearing loss.

Screening of genetic alterations related to non-syndromic hearing loss using MassARRAY iPLEX® technology.

BACKGROUND: Recent advances in molecular genetics have enabled to determine the genetic causes of non-syndromic hearing loss, and more than 100 genes have been related to the phenotype. Due to this extraordinary genetic heterogeneity, a large percentage of patients remain without any molecular diagnosis. This condition imply the need for new methodological strategies in order to detect a greater number of mutations in multiple genes. In this work, we optimized and tested a panel of 86 mutations in 17 different genes screened using a high-throughput genotyping technology to determine the molecular etiology of hearing loss. METHODS: The technology used in this work was the MassARRAY iPLEX® platform. This technology uses silicon chips and DNA amplification products for accurate genotyping by mass spectrometry of previous reported mutations. The generated results were validated using conventional techniques, as direct sequencing, multiplex PCR and RFLP-PCR. RESULTS: An initial genotyping of control subjects, showed failures in 20 % of the selected alterations. To optimize these results, the failed tests were re-designed and new primers were synthesized. Then, the specificity and sensitivity of the panel demonstrated values above 97 %. Additionally, a group of 180 individuals with NSHL without a molecular diagnosis was screened to test the diagnostic value of our panel, and mutations were identified in 30 % of the cases. In 20 % of the individuals, it was possible to explain the etiology of the HL. Mutations in GJB2 gene were the most prevalent, followed by other mutations in in SLC26A4, CDH23, MT-RNR1, MYO15A, and OTOF genes. CONCLUSIONS: The MassARRAY technology has the potential for high-throughput identification of genetic variations. However, we demonstrated that optimization is required to increase the genotyping success and accuracy. The developed panel proved to be efficient and cost-effective, being suitable for applications involving the molecular diagnosis of hearing loss.

HiFocus Helix™ electrode insertion: surgical approach.

BACKGROUND: Cochlear implants have been used for almost 30 years as a device for the rehabilitation of individuals with severe-to-profound hearing loss. One of the important aspects of cochlear implantation is the type of electrode selected and proper insertion of the electrode array in scala tympani to minimize cochlear damage. The HiFocus Helix™ electrode is a precurved design aimed at placing the electrode contacts close to the spiral ganglion cells in the modiolus. The prescribed insertion techniques are intended to minimize the likelihood of damage to the basilar membrane or lateral wall of the cochlea. CASE PRESENTATION: To describe the first insertion of a HiFocus Helix™ electrode in Brazil exposing surgical particularities and device details in a patient with profound hearing loss, due to Mondini's dysplasia. CONCLUSION: No problems were encountered during the surgical procedure. The patient experienced improvement in hearing thresholds and speech perception. The HiFocus Helix™ electrode proved easy to insert and provided expected hearing benefits for the patient. This manuscript indicates that the HiResolution™ Bionic Ear System with HiFocus Helix™ electrode comprise a cochlear implant system that is practical and beneficial for the treatment of severe-to-profound hearing loss.

Single nucleotide polymorphisms of the GJB2 and GJB6 genes are associated with autosomal recessive nonsyndromic hearing loss.

Single nucleotide polymorphisms (SNPs) are important markers in many studies that link DNA sequence variations to phenotypic changes; such studies are expected to advance the understanding of human physiology and elucidate the molecular basis of diseases. The DFNB1 locus, which contains the GJB2 and GJB6 genes, plays a key role in nonsyndromic hearing loss. Previous studies have identified important mutations in this locus, but the contribution of SNPs in the genes has not yet been much investigated. The aim of this study was to investigate the association of nine polymorphisms located within the DFNB1 locus with the occurrence of autosomal recessive nonsyndromic hearing loss (ARNSHL). The SNPs rs3751385 (C/T), rs7994748 (C/T), rs7329857 (C/T), rs7987302 (G/A), rs7322538 (G/A), rs9315400 (C/T), rs877098 (C/T), rs945369 (A/C), and rs7333214 (T/G) were genotyped in 122 deaf patients and 132 healthy controls using allele-specific PCR. There were statistically significant differences between patients and controls, in terms of allelic frequencies in the SNPs rs3751385, rs7994748, rs7329857, rs7987302, rs945369, and rs7333214 (P < 0.05). No significant differences between the two groups were observed for rs7322538, rs9315400, and rs877098. Our results suggest that SNPs present in the GJB2 and GJB6 genes may have an influence on ARNSHL in humans.

Hearing preservation and cochlear implants according to inner ear approach: multicentric evaluation / Preservação auditiva e implante coclear de acordo com a abordagem da orelha interna: avaliação multicêntrica

INTRODUCTION: Electroacoustic stimulation is an excellent option for people with residual hearing in the low frequencies, who obtain insufficient benefit with hearing aids. To be effective, the subject's residual hearing should be preserved during cochlear implant surgery. OBJECTIVES: To evaluate the hearing preservation in patients that underwent implant placement and to compare the results in accordance with the approach to the inner ear. METHODS: 19 subjects underwent a soft surgical technique, and the electrode MED-EL FLEX(tm) EAS, designed to be atraumatic, was used. We evaluated pre- and postoperative tonal audiometric tests with an average of 18.4 months after implantation, to measure the rate of hearing preservation. RESULTS: 17 patients had total or partial preservation of residual hearing; 5 had total hearing preservation and two individuals had no preservation of hearing. The insertion of the electrode occurred through a cochleostomy in 3 patients, and in 2 of these there was no hearing preservation; the other 16 patients experienced electrode insertion through a round window approach. All patients benefited from the cochlear implant, even those who are only using electrical stimulation. CONCLUSION: The hearing preservation occurred in 89.4% of cases. There was no significant difference between the forms of inner ear approach. .

INTRODUÇÃO: A estimulação eletroacústica é uma excelente opção para pessoas com audição residual nas baixas frequências, que obtêm benefício insuficiente com aparelhos auditivos. Para ser eficaz, a audição residual deve ser preservada durante a cirurgia de implante coclear. OBJETIVOS: Avaliar a preservação auditiva de pacientes implantados e comparar os resultados de acordo com a abordagem da orelha interna. MÉTODO: 19 indivíduos foram implantados com uma técnica cirúrgica para preservação auditiva, tendo sido utilizado o eletrodo MED-EL FLEXTM EAS, concebido para ser atraumático. Foram avaliados os exames audiométricos tonais no pré e pós-operatório, com uma média de 18,4 meses após o implante para medir a taxa de preservação da audição residual. RESULTADOS: 17 pacientes tiveram preservação total ou parcial da audição residual; cinco obtiveram preservação da audição total e dois indivíduos não tiveram preservação da audição. A inserção do eletrodo ocorreu por cocleostomia em 3 pacientes; em 2 destes pacientes não houve preservação da audição. Os outros 16 pacientes foram submetidos à abordagem pela janela redonda. Todos os pacientes foram beneficiados com o implante coclear, mesmo aqueles pacientes que utilizando apenas estimulação elétrica. CONCLUSÃO: A preservação auditiva ocorreu em 89,4% dos casos. Não houve diferença significativa entre as formas de abordagem da orelha interna. .

Hearing preservation and cochlear implants according to inner ear approach: multicentric evaluation.

INTRODUCTION: Electroacoustic stimulation is an excellent option for people with residual hearing in the low frequencies, who obtain insufficient benefit with hearing aids. To be effective, the subject's residual hearing should be preserved during cochlear implant surgery. OBJECTIVES: To evaluate the hearing preservation in patients that underwent implant placement and to compare the results in accordance with the approach to the inner ear. METHODS: 19 subjects underwent a soft surgical technique, and the electrode MED-EL FLEX™ EAS, designed to be atraumatic, was used. We evaluated pre- and postoperative tonal audiometric tests with an average of 18.4 months after implantation, to measure the rate of hearing preservation. RESULTS: 17 patients had total or partial preservation of residual hearing; 5 had total hearing preservation and two individuals had no preservation of hearing. The insertion of the electrode occurred through a cochleostomy in 3 patients, and in 2 of these there was no hearing preservation; the other 16 patients experienced electrode insertion through a round window approach. All patients benefited from the cochlear implant, even those who are only using electrical stimulation. CONCLUSION: The hearing preservation occurred in 89.4% of cases. There was no significant difference between the forms of inner ear approach.

Investigação etiológica da deficiência auditiva em neonatos identificados em um programa de triagem auditiva neonatal universal / Etiological investigation of deafness in neonates screened in a universal newborn hearing screening program

Objetivo descrever os resultados da investigação etiológica da deficiência auditiva realizada em neonatos rastreados em um programa de triagem auditiva neonatal universal. Métodos estudo descritivo, transversal e prospectivo. Foram incluídos no estudo todos os neonatos diagnosticados com deficiência auditiva identificados em um programa de triagem auditiva neonatal universal no período de agosto de 2003 a dezembro de 2006. A provável etiologia da deficiência auditiva foi determinada após anamnese detalhada realizada pelo médico otorrinolaringologista; pesquisa das sorologias para toxoplasmose, rubéola, citomegalovírus, herpes, sífilis e HIV; tomografia dos ossos temporais e exames genéticos. Resultados foram diagnosticados 17 sujeitos com deficiência auditiva no período estudado. 64.7% dos casos estudados apresentaram como provável etiologia causas pré-natais, 29.4% causas peri-natais e um sujeito (5,9%) apresentou etiologia desconhecida. Das causas pré-natais, 36.4% tiveram origem genética confirmada e 36.4% etiologia presumida de hereditariedade. Foi confirmada a presença de infecções congênitas em 18.2% dos casos e um sujeito (9%) apresentou anomalia craniofacial como provável etiologia. O grau de perda auditiva mais frequente observado nos sujeitos estudados foi o profundo (47,1%). Conclusão a maior ocorrência de etiologias observada neste estudo foram as de origem pré-natal, seguida das de origem peri-natal. .

Purpose to describe the results of etiology of deaf in neonates screened in a universal newborn hearing screening program. Methods a descriptive, cross-sectional and prospective study. The study included all newborns diagnosed with hearing loss identified in a universal newborn hearing screening program from August 2003 to December 2006. The etiology of deaf was determined after detailed anamnesis performed by the otorhinolaryngologist; survey of serological tests for toxoplasmosis, rubella, cytomegalovirus, herpes, syphilis and HIV; tomography of the temporal bone and genetic tests. Results 17 neonates were diagnosed with hearing loss in the period studied. 64.7% of cases presented as probable causes prenatal etiology, 29.4% perinatal causes and one child (5.9%) had unknown etiology. Of prenatal causes, 36.4% had confirmed genetic origin and 36.4% presumed etiology of heredity. We confirmed the presence of congenital infections in 18.2% of cases and one child (9%) had craniofacial anomalies as a possible etiology. The degree of hearing loss more frequently observed in the subjects studied was the profound (47.1%). Conclusion the increased occurrence of etiologies in this study was of prenatal origin, followed by perinatal origin. .

Programa de saude auditiva em neonatos que permaneceram em UTI e/ou cuidados intermediarios / An auditory health program for neonates in ICU and/or intermediate care settings

Atriagem auditiva, a identificação e intervenção precoces da perda auditiva possibilitam um bom prognóstico para o desenvolvimento infantil. OBJETIVO: Analisar os resultados obtidos pelo Programa de Saúde Auditiva em neonatos que permaneceram em Unidade de Terapia Intensiva-UTI. MÉTODO: Estudo de corte transversal prospectivo. A amostra foi constituída por recém-nascidos, internados em unidade neonatal do CAISM/Unicamp, por pelo menos 48 horas, no período de 13 meses. O procedimento utilizado para triagem auditiva foi o Potencial Evocado Auditivo de Tronco Encefálico Automático-Madsen Accuscreen, próximo à alta hospitalar. As crianças que falharam na triagem foram encaminhadas para diagnóstico audiológico, otorrinolaringológico e genético. RESULTADOS: Fizeram a triagem auditiva 84,7% dos neonatos vivos, sendo realizada em 39,7% dos casos após 30 dias de vida. O diagnóstico mostrou que 63,8% das crianças apresentaram audição normal. A incidência da perda auditiva foi de 4%, sendo de 1,4% para perda do tipo neurossensorial, 0,24% com Espectro da Neuropatia Auditiva e 2,2% do tipo condutiva. CONCLUSÃO: Concluiu-se que a triagem auditiva neonatal não foi universal e nem aplicada, em muitos casos, no primeiro mês de vida. Deve ser realizada antes da alta hospitalar e em de mais de uma etapa. A incidência da perda auditiva foi elevada. .

Auditory screening and early identification and management of patients with hearing loss improve the development prospects of infants. OBJECTIVE: To analyze the outcomes produced by an Auditory Health Program in neonates managed in an intensive care unit. METHOD: This prospective cross-sectional study enrolled neonates referred to the neonatal care unit at hospital CAISM/Unicamp with stays lasting for 48 hours and more within a period of 13 months. Automated monitoring of brainstem auditory evoked potentials was used in the auditory screening of neonates at the time of discharge. Children with poor BAEPs were sent to undergo audiological, otorhinolaryngological, and genetic tests. RESULTS: Auditory screening was performed for 84.7% of the live births; 39.7% were screened at 30 days or more of age. Diagnostic tests revealed that 63.8% of the children had normal hearing. Incidence of hearing loss was 4%; sensorineural hearing loss was observed in 1,4% of the subjects; 0.24% had auditory neuropathy spectrum disorder; and 2.2% had conductive hearing loss. CONCLUSION: Neonatal auditory screening was not offered universally, and nor was it carried out, in many cases, within the child's first month of life. Screening must be performed before neonates are discharged and in more than one stage. A high incidence of hearing loss was observed. .

Optimization of simultaneous screening of the main mutations involved in non-syndromic deafness using the TaqMan® OpenArray™ Genotyping platform.

BACKGROUND: Hearing loss is the most common sensory deficit in humans, affecting approximately 10% of the global population. In developed countries, one in every 500 individuals suffers from severe to profound bilateral sensorineural hearing loss. For those up to 5 years old, the proportion is higher, at 2.7 in 1000 individuals, and for adolescents the average is 3.5 in 1000. Among the causes of hearing loss, more than 50% are related to genetic factors. To date, nearly 150 loci and 64 genes have been associated with hearing loss. Mutations in the GJB2 gene, which encodes connexin 26, constitute the main genetic cause. So far, more than 300 variations have been described in this gene.As a response to the clinical and genetic heterogeneity of hearing loss and the importance of correct molecular diagnosis of individuals with hereditary hearing loss, this study worked in the optimization for a diagnostic protocol employing a high-throughput genotyping technology. METHODS: For this work, was used the TaqMan® OpenArray™ Genotyping platform. This is a high performance, high-throughput technology based on real-time PCR, which enables the evaluation of up to 3072 SNPs (Single Nucleotide Polymorphisms), point mutations, small deletions, and insertions, using a single genotyping plate. For the study, were selected the layout allowing to analyze 32 alterations in 96 individuals simultaneously. In the end, the generated results were validated by conventional techniques, as direct sequencing, Multiplex PCR and RFLP-PCR. RESULTS: A total of 376 individuals were analyzed, of which 94 were healthy controls, totaling 4 plates in duplicate. All 31 of the changes analyzed were present in the nuclear genes GJB2, GJB6, CRYL1, TMC1, SLC26A4, miR-96, and OTOF, and in the mitochondrial genes MT-RNR1 and MT-TS1. The reactions were subsequently validated by established techniques (direct sequencing, multiplex PCR, and RFLP-PCR) that had previously been used to perform molecular screening of hearing loss at the Human Genetics Laboratory of the Center for Molecular Biology and Genetic Engineering (CBMEG), at the State University of Campinas (UNICAMP). In total, 11,656 genotyping reactions were performed. Of these, only 351 reactions failed, representing approximately 3.01% of the total. The average accuracy of genotyping using the OpenArray™ plates was 96.99%. CONCLUSIONS: The results demonstrated the accuracy, low cost, and good reproducibility of the technique, indicating that the TaqMan® OpenArray™ Genotyping Platform is a useful and reliable tool for application in molecular diagnostic testing of hearing loss.

Etiologic and diagnostic evaluation: algorithm for severe to profound sensorineural hearing loss in Brazil.

OBJECTIVE: Evaluation of the effectiveness of imaging and genetic testing, and establishment of a cost-effective diagnostic protocol for the etiologic diagnosis of sensorineural hearing loss (SNHL) in Brazil. DESIGN: Prospective cohort study. STUDY SAMPLE: Analysis of 100 unrelated Brazilian patients with severe to profound bilateral SNHL submitted to cochlear implant (CI) between 2002 and 2010 at the University of Campinas hospital. The study was based upon three groups: individuals with congenital, progressive, and sudden SNHL. RESULTS: After the diagnostic investigation, the number of cases with unknown etiology was reduced from 72 to 42 (a 42% reduction); 25% of cases were due to environmental factors, 19% to genetic causes, and 14% to inner-ear abnormalities or other clinical features. The genetic and imaging findings contributed to the diagnosis of SNHL in 19% and 20% of the cases analysed, respectively. Molecular testing mainly contributed to the diagnosis of patients with congenital SNHL, while the contribution of radiologic examination was higher for individuals with progressive or sudden SNHL. A sequential diagnostic protocol was proposed based on these data. CONCLUSIONS: The proposed diagnostic workup algorithm could provide better optimization of etiologic diagnosis, as well as reduced costs, compared to a simultaneous testing approach.

Molecular analysis of SLC26A4 gene in patients with nonsyndromic hearing loss and EVA: identification of two novel mutations in Brazilian patients.

UNLABELLED: The SLC26A4 gene has been described as the second gene involved in most cases of sensorineural non-syndromic hearing loss, since the first is the GJB2 gene. Recessive mutations in the SLC26A4 gene encoding pendrin, an anion transporter, are responsible for non-syndromic hearing loss associated with an enlarged vestibular aqueduct (EVA) and Pendred syndrome, which causes early hearing loss and affects the thyroid gland. Typically, the hearing loss is profound and prelingual. However, in some individuals, hearing impairment may develop later in childhood and then progress. Over 200 different SLC26A4 mutations have been reported, with each ethnic population having its own distinctive mutant allele series including a few prevalent founder mutations. OBJECTIVE: Perform the screening of the 20 coding exons of SLC26A4 gene in Brazilian deaf individuals with EVA. PATIENTS AND METHODS: Among the 23 unrelated non-syndromic hearing loss Brazilian patients with EVA, in whom no deafness-causing mutations of the GJB2 gene, the direct sequencing was performed to screen the 20 exons and their flanking regions of the SLC26A4 gene. RESULTS: The sequencing results revealed 9 cases (39%) carrying 13 different SLC26A4 mutations, including 11 known mutations (279delT, V138F, T193I, IVS8+1G>A, T410M, Q413R, R409H, L445W, IVS15+5G>A, V609G, and R776C) and 2 novel mutation (G149R and P142L). CONCLUSION: The SLC26A4 mutations have a high carrying rate in non-syndromic hearing loss Brazilian 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.

Genetic and audiologic study in elderly with sensorineural hearing loss.

PURPOSE: This study aimed to correlate probable predisposing factors for sensorineural hearing loss in elderly by investigating the audiologic characteristics and frequency of mutations in genes considered responsible for non-syndromic hearing loss. METHODS: Sixty elderly patients were separated into two groups: the Case Group, composed of 30 individuals, 21 females and nine males, all 60 years old or older and presenting diagnoses of sensorineural hearing loss, and the Control Group, composed of 30 elderly individuals matched to the experimental group by age and gender, presenting normal hearing. The patients underwent anamnesis and pure tone audiometry in frequencies of 250, 500, 1000, 2000, 3000, 4000 and 6000 Hz. Blood samples were collected from each patient for analysis of mutations in nuclear and mitochondrial genes related to non-syndromic sensorineural hearing loss. RESULTS: It was observed a greater tendency to noise exposure and consumption of alcohol in the Case Group. The statistically significant symptoms between the groups were tinnitus and hearing difficulty in several situations as: silent environment, telephone, television, sound location and in church. All the individuals of Case Group presented sensorineural and bilateral hearing loss. The symmetry and progression of the hearing impairment were also statistically significant between the groups. No genetic mutations were identified. CONCLUSION: The most reported symptoms were communication difficulties and tinnitus. The predominant auditory characteristics included sensorineural, bilateral, progressive and symmetrical hearing loss. It was not evidenced a relationship between sensorineural hearing loss in elderly and genes considered responsible for non-syndromic hearing loss as no genetic mutation was found in this study.

An auditory health program for neonates in ICU and/or intermediate care settings.

UNLABELLED: Auditory screening and early identification and management of patients with hearing loss improve the development prospects of infants. OBJECTIVE: To analyze the outcomes produced by an Auditory Health Program in neonates managed in an intensive care unit. METHOD: This prospective cross-sectional study enrolled neonates referred to the neonatal care unit at hospital CAISM/Unicamp with stays lasting for 48 hours and more within a period of 13 months. Automated monitoring of brainstem auditory evoked potentials was used in the auditory screening of neonates at the time of discharge. Children with poor BAEPs were sent to undergo audiological, otorhinolaryngological, and genetic tests. RESULTS: Auditory screening was performed for 84.7% of the live births; 39.7% were screened at 30 days or more of age. Diagnostic tests revealed that 63.8% of the children had normal hearing. Incidence of hearing loss was 4%; sensorineural hearing loss was observed in 1,4% of the subjects; 0.24% had auditory neuropathy spectrum disorder; and 2.2% had conductive hearing loss. CONCLUSION: Neonatal auditory screening was not offered universally, and nor was it carried out, in many cases, within the child's first month of life. Screening must be performed before neonates are discharged and in more than one stage. A high incidence of hearing loss was observed.