Congenital Aural Atresia prevalence in the Argentinian population / Prevalencia de atresia aural congénita en la población argentina

Introduction: Congenital Aural Atresia (CAA) or microtia is a malformation that results in esthetic and functional problems. There is little information on prevalence, considering that Latin American is the most affected region in the world. Objective: To determine the prevalence of microtia, considering the different ethnical structure of the population. Methods: A retrospective analysis was performed of the clinical reports of newborn infants (public hospitals) in three different regions. Results: The incidence of CAA in Argentina was 1 case per 7500 new births (i.e. 1.3/10,000). Marked differences were found per geographical area. The means were calculated per year by bilateral parametric estimation, according to the ethnical origins of the population. In the Caucasoid area: 02.47/10,000 (±1.2), in the Mestizo area: 03.99/10,000 (±0.0) and finally in the Amerindian area: 20.93/10,000 (±0.1). Conclusion: This study shows different incidences according to the demographic features of the population from 1.90/10,000 to 20.9/10,000. This data indicates that CAA is associated with a genetic problem (ethnic differences)

Introducción: La atresia aural congénita (AAC) o microtia es una malformación que produce problemas funcionales y estéticos. Existe falta de información de prevalencia en Argentina, teniendo en cuenta además que Latinoamérica es la región más afectada del mundo. Objetivo: Determinar la prevalencia de microtia, teniendo en cuenta la estructura étnica de la población según las regiones. Métodos: Análisis retrospectivo de historias clínicas en hospitales públicos de recién nacidos en diferentes zonas del país. Resultados: La prevalencia de atresia en Argentina fue de uno de cada 7.500 recién nacidos (1,3/10.000). Se encontraron marcadas diferencias de acuerdo al área geográfica. En el área caucásica: 2,47/10.000 (± 1,2), en el área mestiza: 3,99/10.000 (± 0) y en el área amerindia: 20,93/10.000 (± 0,1). Conclusión: El estudio muestra una diferente incidencia con arreglo a las características demográficas de la población, de entre 1,90/10.000 y 20,9/10.000. Estos datos permitirían asociar la atresia con problemas genéticos (origen étnico)

Congenital Aural Atresia prevalence in the Argentinian population.

INTRODUCTION: Congenital Aural Atresia (CAA) or microtia is a malformation that results in esthetic and functional problems. There is little information on prevalence, considering that Latin American is the most affected region in the world. OBJECTIVE: To determine the prevalence of microtia, considering the different ethnical structure of the population. METHODS: A retrospective analysis was performed of the clinical reports of newborn infants (public hospitals) in three different regions. RESULTS: The incidence of CAA in Argentina was 1 case per 7500 new births (i.e. 1.3/10,000). Marked differences were found per geographical area. The means were calculated per year by bilateral parametric estimation, according to the ethnical origins of the population. In the Caucasoid area: 02.47/10,000 (±1.2), in the Mestizo area: 03.99/10,000 (±0.0) and finally in the Amerindian area: 20.93/10,000 (±0.1). CONCLUSION: This study shows different incidences according to the demographic features of the population from 1.90/10,000 to 20.9/10,000. This data indicates that CAA is associated with a genetic problem (ethnic differences).

Locus DFNB4 -acueducto vestibular dilatado- comportamiento audio-vestibular / Locus DFNB4 -enlarged vestibular aqueduct- behavior audio vestibular / Locus DFNB4 - aqueduto vestibular dilatada - comportamentoaudio-vestibular

Introducción: el acueducto vestibular dilatado, denominado en la literatura internacional EVA, porEnlarged Vestibular Aqueduct, ha sido reportadopor afectar hasta el 15% de la población pediátrica con hipoacusia neurosensorial. En su génesis compartecon Pendred en el Locus DFNB4, el Gen SLC26A4en el cromosma 7q22-31.1. No se conoce bienel comportamiento y la evolución de esta entidad,debido a la gran variabilidad genotípica y fenotípicaque presenta...

Introduction: Dilated Vestibular Aqueduct, known in the international literature Enlarged Vestibular Aqueduct (EVA) has been reported to affect up to 15% of the pediatric population with hearing loss Sensory Neuro. In its genesis shares with pendred in the locus DFNB4 the SLC26A4 gene in the cromosma 7q22-31.1. It is not well understood and evolution behavior of this entity, due to the great variability genotypic and phenotypic presented...

Introdução: Aqueduto vestibular dilatada conhecido na literatura internacional Enlarged Vestibular Aqueduct (EVA) tem sido relatada a afetar até 15% da população pediátrica com perda auditiva sensorial neuro. Em suas ações genesis com Pendred no Locus DFNB4 o gene SLC26A4 na 7q22-31.1 cromosma. Elenão é bem compreendida e o comportamento de evolução dessa entidade, devido à grande variabilidade genotípica e fenotípica apresentada...

Anatomía aplicada a fracturas de temporal: análisis de 10 casos / Applied anatomy of a temporary fracture: analysis of 10 cases / Anatomia aplicada a fraturas de temporal: análise de dez caso

Antecedentes: las lesiones en el hueso temporal ocurren en el 30 a 70% de los casos de traumatismo de cráneo cerrado, siendo los accidentes automovilísticos causa del 31%. En general, las líneas de fractura corren paralelas a la línea del golpe entregado y se extienden a través de los agujeros de la base del cráneo, puntos débiles del hueso temporal. Estas se denominan como longitudinal o transversal, a pesar de que la mayoría son en realidad mixtas. Las fracturas bilaterales tienen una incidencia menor de 8-29%. Objetivo: Analizar los tipos de fracturas temporales más frecuentes y las modificaciones de éstas sobre su anatomía en correlación con la clínica del paciente y los exámenes de TAC. Diseño: Retrospectivo de corte transversal. Población: Niños y adultos jóvenes de ambos sexos. Método: Es un trabajo retrospectivo transversal con revisión de historias clínicas de niños y adultos jóvenes, más disecciones microanatómicas en cadáveres adultos de ambos sexos, fijados en formol al 10%. Resultados: Se recolectaron 10 pacientes; 8 de sexo masculino y 2 femeninos, del total 2 son niños. Todos con procedencia de Córdoba, consultan por zumbido, hipoacusia y mareo o desequilibrio postraumático. Uno de ellos niño de 13 años con hipoacusia bilateral y supuración de oído. Al grupo se suma una parálisis facial recuperada con tratamiento clínico. Conclusiones: El conocimiento de la anatomía, con el apoyo de la tomografía computada de oído, y los estudios audiológicos son fundamentales para el diagnóstico clínico y topográfico de la lesión.

Background: lesions occur in the temporal bone in the 30 to 70% of cases of closed skull trauma. Being car accidents cause 31%. In general, the fracture lines run parallel to the line of blow delivered and extend through the holes to the skull base, temporal bone weak points. These are denominate as longitudinal or transverseal, though most are actually mixed. The bilateral fractures have a lower incidence of 8-29%. Objetive: analize the types of temporal fractures the most frequent and modifications of these on their anatomy correlated with the patient’s clinical and computed tomography exams. Design: transversal cut retrospective. Population: children and young adults of both sexes. Method: it is a transversal retrospective study with review of clinical records of children and young adults more microanatomic dissections in adult cadavers of both sexes, fixed in 10% formalin. Results: 10 patients were collected; 8 male and 2 female, total 2 are children. All of them are from Córdoba, complaining of tinnitus, hearing loss and dizziness or post traumatic imbalance. The age average is to 22 years old. The 50% is given by automobile accidents, also presented cases of labor accident, drop height and flattening. One of them, a child to 13 years old with bilateral hearing loss and ear drainage. The group adds a facial paralysis recovered with clinical treatment. Conclusions: knowledge of anatomy, with supported by computed tomography ear, and audiological studies are essential for clinical diagnosis and topographic of the lesion.

Antecedentes: as lesões no osso temporal ocorrem em 30% a 70% dos casos de traumatismo de crânio fechado, sendo os acidentes automobilísticos causa de 31%. Em geral, as linhas de fratura correm paralelas à linha do golpe e se estendem através dos orifícios da base do crânio, pontos frágeis do osso temporal. Estas são denominadas como longitudinal ou transversal, a pesar de, na verdade, a maioria ser mista. As fraturas bilaterais tem uma incidência menor de 8-29%. Objetivo: Analisar os tipos de fraturas temporais mais frequentes e as modificações destas sobre a sua anatomia em correlação com a clínica do paciente e os exames de TAC. Desenho: Retrospectivo de corte transversal População: Crianças e jovens adultos em ambos os sexos. Método: É um trabalho retrospectivo transversal com revisão de histórias clínicas de crianças e jovens adultos mais dissecações microanatômicas em cadáveres adultos de ambos os sexos, conservados em formol a 10%. Resultados: Foram coletados 10 pacientes: 8 do sexo masculino e 2 femininos, dos quais 2 são crianças. Todos oriundos de Córdoba, consultam por zumbido, hipoacusia e tontura ou desequilíbrio póstraumático. Um desses pacientes, um adolescente de 13 anos com hipoacusia bilateral e supuração do ouvido. Ao grupo, soma-se uma paralisia facial recuperada com tratamento clínico. Conclusões: O conhecimento da anatomia, com o apoio da tomografia computadorizada de ouvido e os estudos audiológicos, é fundamental para o diagnóstico clínico e topográfico da lesão.

Hearing and loud music exposure in 14-15 years old adolescents.

Adolescent exposure to loud music has become a social and health problem whose study demands a holistic approach. The aims of the current study are: (1) To detect early noise-induced hearing loss among adolescents and establish its relationship with their participation in musical recreational activities and (2) to determine sound immission levels in nightclubs and personal music players (PMPs). The participants consisted in 172 14-15 years old adolescents from a technical high school. Conventional and extended high frequency audiometry, transient evoked otoacoustic emissions and questionnaire on recreational habits were administered. Hearing threshold levels (HTLs) were classified as: normal (Group 1), slightly shifted (Group 2), and significantly shifted (Group 3). The musical general exposure (MGE), from participation in recreational musical activities, was categorized in low, moderate, and high exposure. The results revealed an increase of HTL in Group 2 compared with Group 1 (P < 0.01), in Group 3 compared with Group 2 (P < 0.05) only in extended high frequency range, in Group 3 compared with Group 1 (P < 0.01). Besides, a decrease in mean global amplitude, reproducibility and in frequencies amplitude in Group 2 compared with Group 1 (P < 0.05) and in Group 3 compared with Group 1 (P < 0.05). A significant difference (P < 0.05) was found in Group 1's HTL between low and high exposure, showing higher HTL in high exposure. The sound immission measured in nightclubs (107.8-112.2) dBA and PMPs (82.9-104.6) dBA revealed sound levels risky for hearing health according to exposure times. It demonstrates the need to implement preventive and hearing health promoting actions in adolescents.

Hearing and loud music exposure in a group of adolescents at the ages of 14-15 and retested at 17-18.

Young people expose themselves to potentially damaging loud sounds while leisure activities and noise induced hearing loss is diagnosed in increasing number of adolescents. Hearing and music exposure in a group of adolescents of a technical high school was assessed at the ages of: 14-15 (test) and 17-18 (retest). The aims of the current study were: (1) To compare the auditory function between test and retest; (2) to compare the musical exposure levels during recreational activities in test and retest; (3) to compare the auditory function with the musical exposure along time in a subgroup of adolescents. The participants in the test were 172 male; in the retest, this number was reduced to 59. At the test and retest the conventional and extended high frequency audiometry, transient evoked otoacoustic emissions (TEOAEs) and recreational habits questionnaire were performed. In the test, hearing threshold levels (HTLs) were classified as: Normal (Group 1), slightly shifted (Group 2), and significantly shifted (Group 3); the Musical General Exposure (MGE), categorized in: Low, moderate, high, and very high exposure. The results revealed a significant difference (P < 0.0001) between test and retest in the HTL and global amplitude of TEOAEs in Group 1, showing an increase of the HTL and a decrease TEOAEs amplitude. A subgroup of adolescents, with normal hearing and low exposure to music in the test, showed an increase of the HTL according with the categories of MGE in the retest. To implement educational programs for assessing hearing function, ear vulnerability and to promote hearing health, would be advisable.

Identification of four novel connexin 26 mutations in non-syndromic deaf patients: genotype-phenotype analysis in moderate cases.

This paper presents a mutation as well as a genotype-phenotype analysis of the GJB2 and GJB6 genes in 476 samples from non-syndromic unrelated Argentinean deaf patients (104 familial and 372 sporadic cases). Most of them were of prelingual onset (82 %) and 27 % were cochlear implanted. Variation of sequences was detected in 171 of the 474 patients (36 %). Overall, 43 different sequence variations were identified in GJB2 and GJB6. Four of them are reported for the first time in GJB2: c.233dupG, p.Ala78Ser, p.Val190Asp and p.Cys211Tyr. Mutations in GJB6 were detected in 3 % of patients [nine del(GJB6-D13S1830) and three del(GJB6-D13S1854)]. Of the 43 different variations identified in GJB2, 6 were polymorphisms and of the others, 10 (27 %) were truncating and 27 (73 %) were nontruncating. Patients with two truncating mutations had significantly worse hearing impairment than all other groups. Moderate phenotypes were observed in a group of patients carrying biallelic mutations (23 %). This work shows the high prevalence of GJB2 mutations in the Argentinean population and presents an analysis of moderate phenotypes in our cohort.

A multicenter study on the prevalence and spectrum of mutations in the otoferlin gene (OTOF) in subjects with nonsyndromic hearing impairment and auditory neuropathy.

Autosomal recessive nonsyndromic hearing impairment (NSHI) is a heterogeneous condition, for which 53 genetic loci have been reported, and 29 genes have been identified to date. One of these, OTOF, encodes otoferlin, a membrane-anchored calcium-binding protein that plays a role in the exocytosis of synaptic vesicles at the auditory inner hair cell ribbon synapse. We have investigated the prevalence and spectrum of deafness-causing mutations in the OTOF gene. Cohorts of 708 Spanish, 83 Colombian, and 30 Argentinean unrelated subjects with autosomal recessive NSHI were screened for the common p.Gln829X mutation. In compound heterozygotes, the second mutant allele was identified by DNA sequencing. In total, 23 Spanish, two Colombian and two Argentinean subjects were shown to carry two mutant alleles of OTOF. Of these, one Colombian and 13 Spanish subjects presented with auditory neuropathy. In addition, a cohort of 20 unrelated subjects with a diagnosis of auditory neuropathy, from several countries, was screened for mutations in OTOF by DNA sequencing. A total of 11 of these subjects were shown to carry two mutant alleles of OTOF. In total, 18 pathogenic and four neutral novel alleles of the OTOF gene were identified. Haplotype analysis for markers close to OTOF suggests a common founder for the novel c.2905_2923delinsCTCCGAGCGCA mutation, frequently found in Argentina. Our results confirm that mutation of the OTOF gene correlates with a phenotype of prelingual, profound NSHI, and indicate that OTOF mutations are a major cause of inherited auditory neuropathy.

Program for the conservation and promotion of hearing among adolescents.

PURPOSE: We describe a program for the promotion of hearing conservation aimed at the adolescent population. The intent of our program is to (a) detect hearing disorders early, as well as to establish their relation to psychosocial and acoustic factors; (b) devise a follow-up procedure to study relevant variables; (c) evaluate the relation between hearing disorders and genetic factors, and (d) raise the social awareness of the effects of noise and its consequences. METHOD: This program, designed to be carried out over a 7-year period, focuses on participants from technical schools in the city of Cordoba, Argentina. Every student will be examined at age 14-15 years and will be reexamined at age 17-18. There will be a yearly follow-up in those cases in which disorders are detected. RESULTS AND CONCLUSIONS: We discuss the organization and planning of this program, together with its launching in the first of the selected schools. We also describe the findings on the following topics: (a) the hearing data on adolescents (age 14-15 years); (b) their recreational habits, personality traits, and attitudes; and (c) the sound immision characteristics these individuals are exposed to during recreational activities.

[Genetic study of hearing loss in families from Argentina]. / Estudio genético de hipoacusia en familias de Argentina.

Recent advances in molecular genetics as well as improved strategies for the prevention and control of non-syndromic hearing loss (NSHL) have contributed to the rising importance of their inherited causes. In this study we report 32 families from Argentine with one (sporadic) or more (familial) individuals affected. All the families were initially screened for mutations in three autosomal nuclear genes and one mutation in mitochondrial DNA. These genes have been found in a great number of familial or sporadic cases of congenital deafness in Caucasians. The mutant allele 35 del G of connexin 26 (GJB2, locus DFNB1 on 13q12) was present in three families. We have investigated the gene encoding otoferlin (OTOF, locus DFNB9 on 2p22-p23) and we found the Q829X mutation in heterocigosity in two families. We have also identified in heterocigosity the 342-kb deletion of connexin 30 (GJB6, locus DFNB1 on 13q12) in one family. On the other hand, we have not found any patient with mitochondrial mutation. Since the screening for other mutations is very expensive, our main goal is to investigate the most frequent mutations in each separate gene in the argentine population and to develop simple and specific tests for each frequent mutations.

Estudio genético de hipoacusia en familias de Argentina. / [Genetic study of hearing loss in families from Argentina]

Recent advances in molecular genetics as well as improved strategies for the prevention and control of non-syndromic hearing loss (NSHL) have contributed to the rising importance of their inherited causes. In this study we report 32 families from Argentine with one (sporadic) or more (familial) individuals affected. All the families were initially screened for mutations in three autosomal nuclear genes and one mutation in mitochondrial DNA. These genes have been found in a great number of familial or sporadic cases of congenital deafness in Caucasians. The mutant allele 35 del G of connexin 26 (GJB2, locus DFNB1 on 13q12) was present in three families. We have investigated the gene encoding otoferlin (OTOF, locus DFNB9 on 2p22-p23) and we found the Q829X mutation in heterocigosity in two families. We have also identified in heterocigosity the 342-kb deletion of connexin 30 (GJB6, locus DFNB1 on 13q12) in one family. On the other hand, we have not found any patient with mitochondrial mutation. Since the screening for other mutations is very expensive, our main goal is to investigate the most frequent mutations in each separate gene in the argentine population and to develop simple and specific tests for each frequent mutations.

Estudio genético de hipoacusia en familias de Argentina / Genetic study of hearing loss in families from Argentina

Los últimos avances en genética molecular como así también el desarrollo de estrategias para la prevención y control de las hipoacusias no sindrómicas (HNS), han contribuido al esclarecimiento de las causas hereditarias de las mismas. En este estudio, se seleccionaron 32 familias argentinas con uno (esporádico) o más (familiar) individuos afectados. El análisis genético consistió en la búsqueda de tres genes autosómicos nucleares y uno en el ADN mitocondrial. Estos genes se localizaron en un gran número de casos familiares o esporádicos de sorderas congénitas en Caucásicos. El alelo mutado 35 del G de la conexina 26 (GJB2, locus DFNB1 en 13g12) se presentó en tres familias. Además se investigó el gen que codifica otoferlina (OTOF locus DFNB9 en 2p22-23) encontrándose en dos familias la mutación Q829X en heterocigocidad. También se identificó en una familia portadora heterocigota la deleción de 342 Kb en la conexina 30 (GJB6, locus DFNB1 en 13g12). Por otro lado, no encontramos ningún paciente con la mutación mitocondrial. Debido a que la búsqueda de otras mutaciones es demasiado costosa, nuestro principal objetivo es investigar aquellas mas frecuentes en la población argentina, a fin de desarrollar test simples y específicos para cada una de ellas. (AU)

Estudio genético de hipoacusia en familias de Argentina / Genetic study of hearing loss in families from Argentina

Los últimos avances en genética molecular como así también el desarrollo de estrategias para la prevención y control de las hipoacusias no sindrómicas (HNS), han contribuido al esclarecimiento de las causas hereditarias de las mismas. En este estudio, se seleccionaron 32 familias argentinas con uno (esporádico) o más (familiar) individuos afectados. El análisis genético consistió en la búsqueda de tres genes autosómicos nucleares y uno en el ADN mitocondrial. Estos genes se localizaron en un gran número de casos familiares o esporádicos de sorderas congénitas en Caucásicos. El alelo mutado 35 del G de la conexina 26 (GJB2, locus DFNB1 en 13g12) se presentó en tres familias. Además se investigó el gen que codifica otoferlina (OTOF locus DFNB9 en 2p22-23) encontrándose en dos familias la mutación Q829X en heterocigocidad. También se identificó en una familia portadora heterocigota la deleción de 342 Kb en la conexina 30 (GJB6, locus DFNB1 en 13g12). Por otro lado, no encontramos ningún paciente con la mutación mitocondrial. Debido a que la búsqueda de otras mutaciones es demasiado costosa, nuestro principal objetivo es investigar aquellas mas frecuentes en la población argentina, a fin de desarrollar test simples y específicos para cada una de ellas.