Assuntos
Anormalidades Múltiplas/genética , Anodontia/genética , Surdez/genética , Orelha Interna/anormalidades , Deformidades Congênitas do Pé/genética , Deformidades Congênitas da Mão/genética , Tálus/anormalidades , Anormalidades Múltiplas/patologia , Pré-Escolar , Cromossomos Humanos Par 7 , Surdez/patologia , Orelha Média/anormalidades , Displasia Ectodérmica/genética , Fácies , Deformidades Congênitas do Pé/diagnóstico por imagem , Deformidades Congênitas do Pé/patologia , Perda Auditiva Neurossensorial/genética , Perda Auditiva Neurossensorial/patologia , Humanos , Masculino , Repetições de Microssatélites , Radiografia , Deleção de Sequência , SíndromeRESUMO
OBJECTIVE: The aim of this study was to determine whether universal newborn hearing screening (UNHS) is effective in increasing the number of children whose hearing impairment is detected early, i.e. within the first 6 months of life. It also investigated whether UNHS contributes most to the early detection of moderately and severely hearing-impaired newborns, as suggested by a recently published report. METHODS: The study consisted of a retrospective analysis of the data of all children born in Tyrol between 1980 and 1999 and having an at least moderate permanent hearing loss in the better ear. RESULTS: The findings are that since UNHS was introduced in some newborn nurseries in 1995, a substantially higher number of hearing-impaired children has been detected early. For the whole sample, the increase of the early detection rate is 39.9%, with a 95% confidence interval of 33.2-46.8% (P<0.0001). For moderate hearing loss the increase is 49.2 with a 95% confidence intervall of 39.6-58.8% (P=0.000). CONCLUSIONS: On the whole, our findings lend support to the view that UNHS is effective in early detection of congenital hearing impairment. We conclude that UNHS provides the greatest benefit for moderately hearing-impaired children who, otherwise, would have been detected last.
Assuntos
Transtornos da Audição , Programas de Rastreamento , Transtornos da Audição/congênito , Transtornos da Audição/diagnóstico , Transtornos da Audição/epidemiologia , Humanos , Lactente , Bem-Estar do Lactente , Estudos Retrospectivos , Índice de Gravidade de DoençaRESUMO
Mutations of the connexin 26 (Cx26) gene cause isolated recessive or dominant hearing loss or both sensorineural hearing impairment and keratoderma. We have identified the first de novo mutation of the Cx26 gene, R75 W, in a sporadic case of isolated profound hearing loss. R75 W has been previously observed in association with hearing impairment and keratoderma in one family and is thus thought to cause both syndromic and non-syndromic hearing loss. This case illustrates the risk of a possible erroneous diagnosis of autosomal recessive hearing loss in a sporadic case.
Assuntos
Conexinas/genética , Perda Auditiva Neurossensorial/genética , Substituição de Aminoácidos , Criança , Conexina 26 , DNA/química , DNA/genética , Análise Mutacional de DNA , Genes Dominantes , Humanos , Masculino , Mutação , Mutação Puntual , Polimorfismo Conformacional de Fita SimplesRESUMO
A clinical evaluation and Cx26 mutation analysis was performed in 92 consecutive patients with sensorineural hearing loss in order to delineate the spectrum of genetically caused hearing loss. Among patients of Austrian origin, 53% were classified with hereditary hearing loss. Cx26 mutations were found in 26% of NSHL patients (40% of familial vs 18% of sporadic cases). The mutation 35delG accounted for 52.8% of all presumed GJB2 disease alleles. The second most frequent mutation was L90P (16.7%) having been reported with a prevalence of 0.7-3.5% in other populations. Three novel mutations were found. The novel mutation, R143Q, was associated with dominant high-frequency hearing loss. Pseudodominant transmission of NSHL was seen in four families with Cx26 mutations. A mutation 35delG carrier rate of 0.9% was observed among 672 controls from West-Austria. Cx26 mutations were found associated with mild to profound, and with asymmetric hearing impairment.