Made available in DSpace on 2014-06-11T19:23:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-12-20Bitstream added on 2014-06-13T19:08:46Z : No. of bitstreams: 1 moreira_dtoc_me_botfm.pdf: 857123 bytes, checksum: 211a3514002e4229b7f57e353a2ac0f0 (MD5) / A deficiência auditiva é o déficit sensorial mais comum e tem dentre as suas diferentes etiologias as alterações genéticas. Mutações na conexina 26 são comuns, e uma mutação específica no gene GJB2 é a 35delG, a mais encontrada na deficiência auditiva hereditária não sindrômica. Investigar a ocorrência da mutação 35delG, em pacientes com deficiência auditiva sensorioneural não sindrômica (DASNNS) e de seus parentes em primeiro grau com o mesmo tipo de disacusia assim como naqueles com audição dentro dos padrões de normalidade. Participaram do estudo 72 indivíduos, atendidos no Serviço de Saúde Auditiva do Centro de Reabilitação dos Distúrbios da Audição e Comunicação (CERDAC), do Hospital das Clínicas da Faculdade de Medicina de Botucatu‐ UNESP. Estes indivíduos foram divididos em três grupos ‐ Grupo A: 58 casos com DASNNS; Grupo B: 09 casos (parentes em primeiro grau do grupo A) com DASNNS e Grupo C: 05 indivíduos parentes em primeiro grau do grupo A com audição dentro dos padrões de normalidade. Todos foram submetidos à avaliação audiológica e investigação genética para o rastreamento da mutação 35delG. 67 casos apresentaram deficiência auditiva sensorioneural não sindrômica (DASNNS) ‐ Grupos A e B, e 05 indivíduos com audição dentro dos padrões de normalidade (Grupo C). Quanto às mutações 35delG encontradas, quatro foram mutações em heterozigose, três delas encontradas em uma mesma família: pai (38anos), mãe (28 anos) e filho (05 anos) afetados. Nesta família, os pais eram ouvintes normais e o filho apresentou DASNNS pré‐lingual de grau grave bilateral. A outra mutação em heterozigose foi encontrada em paciente do sexo feminino, 38 anos, com DASNNS pré‐lingual de grau moderado bilateral. A única mutação em homozigose foi em um paciente do sexo masculino... / Hearing impairment is the most common sensory deficit and has among its different etiologies the genetic disorders. Mutations in connexin 26 are common and a specific mutation in the gene GJB2 is the 35delG, the most commonly found in hereditary non‐syndromic deafness. To investigate the occurrence of the 35delG mutation in patients with non‐syndromic sensorineural hearing loss (NS‐SNHL) and their first‐degree relatives with the same type of hearing loss as well as those with normal hearing. The study included 72 patients from the Division of Hearing Health of the Hearing and Communication Disorders Rehabilitation Center (CERDAC), Botucatu Medical School Hospital, UNESP. These individuals were divided into three groups ‐ Group A: 58 cases with NS‐SNHL, Group B: 09 cases (first‐degree relatives of group A) with NS‐SNHL and Group C: 05 cases with normal hearing, first‐degree relatives of patients from group A. All patients were submitted to audiologic evaluation and genetic testing of the 35delG mutation. 67 patients had non‐syndromic sensorineural hearing loss (NS‐SNHL) ‐ Groups A and B, and 05 individuals had normal hearing (Group C). As for 35delG mutations found, four were heterozygous mutations, three of them found in the same family: father (38 years old), mother (28 years old) and son (05 years old) affected. In this family, the parents had normal hearing and the child had severe prelingual NS‐SNHL. The other heterozygous mutation was found in a female patient, 38 years old, with bilateral moderate pre‐lingual NS‐SNHL. A single homozygous mutation was found in a male patient, 20 years old, with a severe pre‐lingual SNHL in his right ear and a profound SNHL in his left ear. The study of the 35delG mutation was found to be easy to perform and inexpensive; it was possible to determine the... (Complete abstract click electronic access below)

Objetivos: estabelecer o diagnóstico de uma amostra de indivíduos com deficiência auditiva (DA) e comprometimento de outras estruturas anatômicas e/ou sistemas fisiológicos, cadastrados no CEDALVI/HRAC-USP-Bauru; verificar possíveis fatores etiológicos envolvidos e investigar possível correlação do tipo de DA com as diferentes síndromes encontradas. Local: Serviço de Genética Clínica do CEDALVI/HRAC-USP, Bauru-SP. Participantes: 93 indivíduos com DA e comprometimento de outras estruturas anatômicas e/ou sistemas fisiológicos. Intervenções: Avaliação genética-clínica; estudo citogenético; avaliações radiológica, oftalmológica, otorrinolaringológica, audiológica e outras. Resultados: Dos 93 indivíduos, 51 eram do sexo masculino e 42, do feminino. Recorrência familial foi observada em 31 casos e, consangüinidade parental em 8. Na amostra, 25 síndromes gênicas conhecidas, 5 síndromes cromossômicas, 5 quadros de etiologia ambiental e 2 quadros de etiologia heterogênea foram estabelecidos em 87 indivíduos. Em 1 caso, não foi possível definir entre 2 condições gênicas e em 5, não foi possível se chegar a um diagnóstico. Conclusões: a casuística se compôs de síndromes etiologicamente heterogêneas, com maior freqüência de etiologia genética; o tipo de DA nas síndromes gênicas foi condizente com o quadro diagnosticado; 3 indivíduos apresentaram síndromes ambientais clássicas, com diferentes tipos de DA; 2 indivíduos apresentaram quadro clínico, possivelmente decorrente de efeito teratogênico; implicação direta de fatores de risco para DA, na etiologia dessa, nos indivíduos com síndromes gênicas conhecidas sem DA; 1 caso, possivelmente, representa uma síndrome nova de padrão único, de etiologia desconhecida; o aconselhamento genético está na dependência da fase em que se encontra o processo de delineamento das diferentes condições estabelecidas. / Objectives: The purposes of this study were to establish the diagnostic of the individuals with hearing loss and presenting other additional anatomic structures and/or physiologic systems involvement, recorded in the CEDALVI/HRAC-USP-Bauru; to verify possible etiologic factors involved and to investigate a possible correlation of the hearing loss type with the different diagnosis syndromes. Setting: Clinical genetic service of the CEDALVI/HRAC-USP, Bauru- P. Participants: The sample was comprised of 93 individuals with hearing loss and involvement of other anatomic structures and/or physiologic systems. Interventions: Clinical genetic evaluation; cytogenetic study; radiological, ophtalmological, othorinolaryngological, audiologycal evaluation, etc. Results: From the total of the sample, 51 were male and 42 were female. Familial recurrence was observed in 31 cases and parental consanguinity in 8. In the present sample, 25 known genic syndromes, 5 chromosomal syndromes, 5 environmental conditions, and 2 heterogeneous conditions were established in 87 individuals. The diagnosis was not established in 5 individuals and in 1 case it was not possible to define between 2 genic conditions. Conclusions: The casuistic was composed of etiologically heterogeneous syndromes with greater frequency of genetic etiology; the type of hearing loss in the genic syndromes was concordant with the diagnosed condition; 3 individuals presented classic environmental syndromes with different types of hearing loss; 2 individuals presented clinical picture, possibly due to teratogenic effect; hearing impairment related to risk factors of the hearing loss in the individuals with known genic syndromes without hearing loss; probable a new unique-pattern syndrome, of unknown etiology in 1 case; the genetic counseling will depend on the step of delineation process of the different diagnosed condition.

Objetivos: estabelecer o diagnóstico de uma amostra de indivíduos com deficiência auditiva (DA) e comprometimento de outras estruturas anatômicas e/ou sistemas fisiológicos, cadastrados no CEDALVI/HRAC-USP-Bauru; verificar possíveis fatores etiológicos envolvidos e investigar possível correlação do tipo de DA com as diferentes síndromes encontradas. Local: Serviço de Genética Clínica do CEDALVI/HRAC-USP, Bauru-SP. Participantes: 93 indivíduos com DA e comprometimento de outras estruturas anatômicas e/ou sistemas fisiológicos. Intervenções: Avaliação genética-clínica; estudo citogenético; avaliações radiológica, oftalmológica, otorrinolaringológica, audiológica e outras. Resultados: Dos 93 indivíduos, 51 eram do sexo masculino e 42, do feminino. Recorrência familial foi observada em 31 casos e, consangüinidade parental em 8. Na amostra, 25 síndromes gênicas conhecidas, 5 síndromes cromossômicas, 5 quadros de etiologia ambiental e 2 quadros de etiologia heterogênea foram estabelecidos em 87 indivíduos. Em 1 caso, não foi possível definir entre 2 condições gênicas e em 5, não foi possível se chegar a um diagnóstico. Conclusões: a casuística se compôs de síndromes etiologicamente heterogêneas, com maior freqüência de etiologia genética; o tipo de DA nas síndromes gênicas foi condizente com o quadro diagnosticado; 3 indivíduos apresentaram síndromes ambientais clássicas, com diferentes tipos de DA; 2 indivíduos apresentaram quadro clínico, possivelmente decorrente de efeito teratogênico; implicação direta de fatores de risco para DA, na etiologia dessa, nos indivíduos com síndromes gênicas conhecidas sem DA; 1 caso, possivelmente, representa uma síndrome nova de padrão único, de etiologia desconhecida; o aconselhamento genético está na dependência da fase em que se encontra o processo de delineamento das diferentes condições estabelecidas. / Objectives: The purposes of this study were to establish the diagnostic of the individuals with hearing loss and presenting other additional anatomic structures and/or physiologic systems involvement, recorded in the CEDALVI/HRAC-USP-Bauru; to verify possible etiologic factors involved and to investigate a possible correlation of the hearing loss type with the different diagnosis syndromes. Setting: Clinical genetic service of the CEDALVI/HRAC-USP, Bauru- P. Participants: The sample was comprised of 93 individuals with hearing loss and involvement of other anatomic structures and/or physiologic systems. Interventions: Clinical genetic evaluation; cytogenetic study; radiological, ophtalmological, othorinolaryngological, audiologycal evaluation, etc. Results: From the total of the sample, 51 were male and 42 were female. Familial recurrence was observed in 31 cases and parental consanguinity in 8. In the present sample, 25 known genic syndromes, 5 chromosomal syndromes, 5 environmental conditions, and 2 heterogeneous conditions were established in 87 individuals. The diagnosis was not established in 5 individuals and in 1 case it was not possible to define between 2 genic conditions. Conclusions: The casuistic was composed of etiologically heterogeneous syndromes with greater frequency of genetic etiology; the type of hearing loss in the genic syndromes was concordant with the diagnosed condition; 3 individuals presented classic environmental syndromes with different types of hearing loss; 2 individuals presented clinical picture, possibly due to teratogenic effect; hearing impairment related to risk factors of the hearing loss in the individuals with known genic syndromes without hearing loss; probable a new unique-pattern syndrome, of unknown etiology in 1 case; the genetic counseling will depend on the step of delineation process of the different diagnosed condition.

Orientador: Jair Cortez Montovani / Banca: Victor Nakajima / Banca: Luciana Paula Maximo / Resumo: A deficiência auditiva é o déficit sensorial mais comum e tem dentre as suas diferentes etiologias as alterações genéticas. Mutações na conexina 26 são comuns, e uma mutação específica no gene GJB2 é a 35delG, a mais encontrada na deficiência auditiva hereditária não sindrômica. Investigar a ocorrência da mutação 35delG, em pacientes com deficiência auditiva sensorioneural não sindrômica (DASNNS) e de seus parentes em primeiro grau com o mesmo tipo de disacusia assim como naqueles com audição dentro dos padrões de normalidade. Participaram do estudo 72 indivíduos, atendidos no Serviço de Saúde Auditiva do Centro de Reabilitação dos Distúrbios da Audição e Comunicação (CERDAC), do Hospital das Clínicas da Faculdade de Medicina de Botucatu‐ UNESP. Estes indivíduos foram divididos em três grupos ‐ Grupo A: 58 casos com DASNNS; Grupo B: 09 casos (parentes em primeiro grau do grupo A) com DASNNS e Grupo C: 05 indivíduos parentes em primeiro grau do grupo A com audição dentro dos padrões de normalidade. Todos foram submetidos à avaliação audiológica e investigação genética para o rastreamento da mutação 35delG. 67 casos apresentaram deficiência auditiva sensorioneural não sindrômica (DASNNS) ‐ Grupos A e B, e 05 indivíduos com audição dentro dos padrões de normalidade (Grupo C). Quanto às mutações 35delG encontradas, quatro foram mutações em heterozigose, três delas encontradas em uma mesma família: pai (38anos), mãe (28 anos) e filho (05 anos) afetados. Nesta família, os pais eram ouvintes normais e o filho apresentou DASNNS pré‐lingual de grau grave bilateral. A outra mutação em heterozigose foi encontrada em paciente do sexo feminino, 38 anos, com DASNNS pré‐lingual de grau moderado bilateral. A única mutação em homozigose foi em um paciente do sexo masculino... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Hearing impairment is the most common sensory deficit and has among its different etiologies the genetic disorders. Mutations in connexin 26 are common and a specific mutation in the gene GJB2 is the 35delG, the most commonly found in hereditary non‐syndromic deafness. To investigate the occurrence of the 35delG mutation in patients with non‐syndromic sensorineural hearing loss (NS‐SNHL) and their first‐degree relatives with the same type of hearing loss as well as those with normal hearing. The study included 72 patients from the Division of Hearing Health of the Hearing and Communication Disorders Rehabilitation Center (CERDAC), Botucatu Medical School Hospital, UNESP. These individuals were divided into three groups ‐ Group A: 58 cases with NS‐SNHL, Group B: 09 cases (first‐degree relatives of group A) with NS‐SNHL and Group C: 05 cases with normal hearing, first‐degree relatives of patients from group A. All patients were submitted to audiologic evaluation and genetic testing of the 35delG mutation. 67 patients had non‐syndromic sensorineural hearing loss (NS‐SNHL) ‐ Groups A and B, and 05 individuals had normal hearing (Group C). As for 35delG mutations found, four were heterozygous mutations, three of them found in the same family: father (38 years old), mother (28 years old) and son (05 years old) affected. In this family, the parents had normal hearing and the child had severe prelingual NS‐SNHL. The other heterozygous mutation was found in a female patient, 38 years old, with bilateral moderate pre‐lingual NS‐SNHL. A single homozygous mutation was found in a male patient, 20 years old, with a severe pre‐lingual SNHL in his right ear and a profound SNHL in his left ear. The study of the 35delG mutation was found to be easy to perform and inexpensive; it was possible to determine the... (Complete abstract click electronic access below) / Mestre

No description available.

Surdez e perda auditiva são termos utilizados para designar distúrbios da audição, o tipo de deficiência sensorial mais frequente em humanos e decorrente de alterações genéticas em cerca de 50% dos casos. A heterogeneidade de lócus, de alelos e de manifestações fenotípicas na surdez é impressionante. O lócus DFNB1, que contém os genes GJB2 e GJB6, é responsável por cerca de 40% dos casos de surdez não-sindrômica de origem genética, porém, variantes patogênicas em cerca de 150 genes são descritas como causa de surdez, que pode ser sindrômica ou não-sindrômica. Por permitirem o sequenciamento simultâneo de diversos genes em uma mesma análise, as técnicas de sequenciamento de nova geração têm sido empregadas para o diagnóstico molecular de condições geneticamente heterogêneas, incluindo a surdez. O objetivo desse estudo foi contribuir para o estudo da heterogeneidade genética da surdez por meio do sequenciamento de nova geração de um painel com 99 genes relacionados à perda auditiva. Indivíduos não aparentados de 91 famílias brasileiras, com provável causa genética de surdez, foram avaliados com o intuito de identificar as causas moleculares da surdez, detectar novas variantes e promover aconselhamento genético das famílias participantes do estudo. Variantes provavelmente causais foram detectadas em 41 dos 91 probandos analisados (45,1%), dos quais 34 (37,4%) apresentaram variantes patogênicas ou provavelmente patogênicas. Nos outros 7 casos, foram detectadas variantes de efeito desconhecido com elevado potencial de explicar a perda auditiva dos probandos. As taxas de detecção nos casos de provável surdez sindrômica foram de 44,4% no grupo com suspeita de síndrome de Waardenburg (4 de 9 casos) e de 61,5% no grupo com suspeita de síndrome de Usher (8 de 13 casos). Nos casos de surdez não-sindrômica, as taxas de detecção foram de 53,9% no grupo com provável surdez autossômica dominante, 35,1% no grupo com provável surdez autossômica recessiva e de 45,0 % no grupo com mais de um mecanismo de herança possível. Das 43 variantes classificadas como patogênicas ou provavelmente patogênicas detectadas nesse estudo, 15 nunca haviam sido descritas. Contribuições científicas importantes foram obtidas com a identificação de uma nova variante de perda de função no gene CEACAM16 como causa de surdez não-sindrômica autossômica recessiva e com a confirmação de uma variante no gene MYO3A como causa de surdez não-sindrômica autossômica dominante recém-descrita em famílias brasileiras. Os resultados obtidos permitiram concluir que o sequenciamento de nova geração de paineis multigênicos é uma estratégia eficaz para o estudo da heterogeneidade genética da surdez, contribuindo para a detecção de novas variantes, ampliando o conhecimento científico a respeito dos genes analisados, e para o aconselhamento genético dos indivíduos estudados e seus familiares / Deafness and hearing loss are terms used to describe hearing disorders, the most common type of sensory impairment in humans, which occurs due to genetic alterations in about 50% of cases. The heterogeneity of locus, alleles and phenotypic manifestations of deafness is striking. The DFNB1 locus, which contains the genes GJB2 and GJB6, is responsible for about 40% of cases of non-syndromic genetic hearing loss, but pathogenic variants in near 150 genes are described as causing deafness, which may be syndromic or non-syndromic. By allowing the simultaneous sequencing of several genes in the same analysis, next-generation sequencing techniques have been employed for the molecular diagnosis of genetically heterogeneous conditions, including deafness. The aim of this study was to contribute to the study of the genetic heterogeneity of deafness employing the next-generation sequencing of a panel with 99 genes related to hearing loss. Individuals from 91 unrelated Brazilian families, with a probable genetic cause for deafness, were evaluated with the purpose of identifying the molecular causes of deafness, to detect new variants and to provide genetic counseling to the families enrolled in the study. Probably causal variants were detected in 41 of the 91 probands analyzed (45.1%), of which 34 (37.4%) had pathogenic or likely pathogenic variants. In the other 7 cases, variants of unknown significance with high potential to explain the hearing loss were detected. Detection rates in cases of probable syndromic deafness were 44.4% in the group with suspected Waardenburg syndrome (4 of 9 cases) and 61.5% in the group with suspected Usher syndrome (8 of 13 cases). In cases of non-syndromic deafness, detection rates were 53.9% in the group with probable autosomal dominant inheritance, 35.1% in the group with probable autosomal recessive inheritance and 45.0% in the group with more than one possible mechanism of inheritance. Among the 43 variants classified as pathogenic or probably pathogenic detected in this study, 15 had never been described. Important scientific contributions were obtained such as the identification of a novel loss-of-function variant in the CEACAM16 gene as causing autosomal recessive non-syndromic deafness and the confirmation of a recently described variant in the MYO3A gene as causing autosomal dominant non-syndromic deafness in Brazilian families. The results obtained allowed us to conclude that next-generation sequencing of multigenic panels is an effective strategy for the study of the genetic heterogeneity of deafness, contributing to the detection of new variants, expanding scientific knowledge about the genes analyzed, and also to the genetic counseling of the individuals studied and their relatives

The aetiological diagnosis of recessive non-syndromic hearing loss poses a challenge owing to marked heterogeneity and the lack of identifying clinical features. The finding that up to 50% of recessive non-syndromal genetic hearing loss among Caucasians was due to mutations in GJB2, the gene encoding Connexin 26 (Cx26) was a breakthrough, whose value as a diagnostic tool has been limited by the significant variation in the prevalence of deafness genes and loci among population groups. The significant association of the GJB6-D13S1830 deletion among individuals with one mutant GJB2 allele highlighted the need to explore population specific genetic mutations for NSHL. Although data from Sub-Saharan Africa is limited, reported studies found a high prevalence of R143W GJB2 mutation among Ghanaian, the 35delG mutation in 5 out of 139 Sudanese and a low prevalence of GJB2 variations among 385 Kenyan deaf children. The mutation spectrum of Waardenburg Syndrome (WS) in Africans has not been documented. During a visit to a School for the Deaf in the Limpopo Province of South Africa in 1997, it was noted that a high number of students came from Nzhelele sub-district. All had childhood onset hearing loss with no associated anomalies or disorders. The question arose as to whether there was a high-risk area for deafness in the Limpopo Province and what the aetiology of this hearing loss was.The main aim of this study was to investigate the role of GJB2, the GJB6-D13S1830 deletion, and the four common mitochondrial mutations, A1555G, A3243G, A7511C and A7445G, in the African hearing-impaired population of Limpopo province in South Africa, and to identify the mutation spectrum of the deafness genes found. The type and degree of hearing loss in this hearing impaired population would also be assessed. Secondly, this study sought to identify the mutations in a sibling pair with 2 clinical WS and to use the findings in a future study to establish the mutation spectrum of WS in the African population of the Limpopo province and of South Africa in general. The study was designed as a two phase study, in which phase 1 was used for hypothesis formulation and phase 2 was for hypothesis testing. While phase 1 was a descriptive retrospective case study, phase 2 was a combination of sample survey and prospective descriptive case study. In phase 1, demographic data of 361 students in two schools of the deaf in the Limpopo province was analyzed for evidence of areas of high risk populations for deafness in the province. In phase 2, a group of 182 individuals with genetic non-syndromic hearing loss (NSHL) and two siblings with clinical WS from two schools for the Deaf in the Limpopo Province of South Africa were investigated. A thorough clinical examination, audiological evaluation and urinalysis were done. Mutational screening was carried out in all 184 subjects using genomic DNA using single-strand conformation polymorphism (SSCP), multiplex polymerase chain reaction (PCR), and direct sequencing for GJB2, and Restriction Fragment-Length Polymorphism (PCR–RFLP) analysis for GJB6, and SSCP, hetero-duplex analysis, and direct sequencing of the first 8 exons of PAX3 and all of MITF for Waarenburg syndrome. Data analysis was by geographical mapping, frequency tables, tests of association with calculation of odds ratios, and binary logistic regression analysis using STATA and GIS mapping systems. The results indicate that there seem to be areas of genuine populations at risk for hearing loss in the Limpopo province of South Africa, namely Mutale and parts of Makhado and Thulamela municipalities. In Thulamela (NP343) wards 11-15, 26-30 and 31-35, and in Mutale (NP 344) wards 6-10, together accounted for 67 (18%) of participants in phase 1, and 33 (18%) of the participants in phase 2 of the study. Mutale municipality in the Vhembe 3 district gave with a projected prevalence of at least 13.14 deaf children per 100,000 African population attending the local school for the deaf. The observed hearing loss is a genetic, non-syndromic form, which is mainly severe and severe to profound, although without any clear defining configuration or shape. It is a stable, non-progressive and prelingual form of hearing loss, implying that this may be a recessive form of deafness. No identifiable environmental confounding factors or associations were identified. The deafness is not linked the common known auditory gene mutations in GJB2, the GJB6-D13S1830 deletion, or the common mitochondrial mutations A1555G, A3243G, A7511C and A7445G. Severe and profound levels of hearing loss were found in 22.8% and 75% of the cohort respectively, with the majority exhibiting flat (70.1%) or sloping (23.4%) audiograms that were commonly symmetrical (81.5%). However, as indicated, there was no clear pattern in the audiological findings overall. None of the 184 hearing impaired individuals exhibited any of the reported disease causing mutations of GJB2, including 35delG. There was, however, a high prevalence of two variants, the C>T variant at position g.3318-15 and the C>T variant at position g.3318-34, occurring in 21.4% and 46.2% of the deaf cohort respectively. The same variants were found to occur in 35% and 42.6% of a normal hearing control group (n = 63) respectively, indicating that these variations are polymorphisms. In three subjects (1.63% of the cohort), a T>A homozygous variation at position g.3318-6 was detected. Its significance in the causation of NSSNHL is yet to be determined. The GJB6-D13S1830 deletion was not detected in any of the participants. None of the four mitochondrial mutations screened for were found. 4 These results indicate that GJB2 is not a significant deafness gene in the African population of the Limpopo Province of South Africa and that significant genes for non-syndromic recessive hearing loss in this population are yet to be found. The geographical clustering of deafness found in this study, combined with the lack of identifiable common associated clinical features among the subjects of this study (excluding the WS sibling pair), suggests that these subjects have a genetic recessive non-syndromal type of hearing loss. In the context of historical and cultural evidence of consanguinity in this population, a founder effect cannot be ruled out. A rare mutation, R223X, previously identified only once out of 470 WS patients, was identified in the PAX3 gene among the WS sibling pair. A novel silent change GGG>GGT at amino acid 293, was also identified. These identical findings document, for the first time, a molecular defect in WS in an African sibling pair, and confirm WS Type I in this family, which could be found in other WS type I South Africans in the Limpopo Province of South Africa. The current study demonstrated that parents of genetically hearing impaired children in these areas are able to detect hearing loss at an early age, with over 60% suspecting their children’s hearing loss below 6 months of age. A child-centered management model encompassing all the areas relevant to childhood deafness/hearing impairment, which takes into consideration the prevailing logistical and financial constraints of the available healthcare system, is proposed. The implementation of this model requires a paradigm shift from the current fragmented model of service delivery to a cohesive patient-centered approach, based on concrete data from appropriate community based research, in which all the relevant parties communicate and share resources. 5 It would achieve the goals of early detection and intervention, as well as inclusive education for all. The relevant health and education policies are already in place and the posts funded. Equitable implementation of these policies would require appropriate community based research, as well as improved communication and consultation between the various stakeholders to ensure an efficient and affordable quality healthcare service for all hearing impaired South Africans.