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1.
Am J Trop Med Hyg ; 96(3): 653-655, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28138053

RESUMO

This report describes a case of mucosal leishmaniasis caused by Leishmania major with destructive perforation of the nasal septum illustrating the diagnostic challenges of a rare clinical presentation of L. major infection in a traveler. The atypical presentation may have been associated with the use of cortisone as a potential trigger for the progressive destruction of the nasal septum.


Assuntos
Leishmania major/isolamento & purificação , Leishmaniose Mucocutânea/diagnóstico , Septo Nasal/patologia , Septo Nasal/parasitologia , Administração Intravenosa , Adulto , Anfotericina B/uso terapêutico , Humanos , Leishmaniose Mucocutânea/tratamento farmacológico , Masculino
2.
Acta Otolaryngol ; 137(4): 356-360, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27827000

RESUMO

CONCLUSION: Alterations within a novel putative Exon 1a within the gap junction beta 2 (GJB2) gene may play a role in the development of genetic hearing impairment in Austria. OBJECTIVES: Mutations in the GJB2 gene are the most common cause of hereditary sensorineural deafness. Genome-wide screening for alternative transcriptional start sites in the human genome has revealed the presence of an additional GJB2 exon (E1a). This study tested the hypothesis of whether alternative GJB2 transcription involving E1a may play a role in the development of congenital sensorineural deafness in Austria. METHODS: GJB2 E1a and flanking regions were sequenced in randomized normal hearing control subjects and three different patient groups with non-syndromic hearing impairment (NSHI), and bioinformatic analysis was performed. Statistical analysis of disease association was carried out using the Cochran-Armitage test for trend. RESULTS: A single change 2410 bp proximal to the translational start site (c.-2410T > C, rs7994748, NM_004004.5:c.-23 + 792T > C) was found to be significantly associated with the common c.35delG GJB2 mutation (p = .009). c.35delG in combination with c.-2410CC occurred at a 6.9-fold increased frequency compared to the control group. Additionally, one patient with idiopathic congenital hearing loss was found to be homozygous c.-2410CC.


Assuntos
Conexinas/genética , Perda Auditiva Neurossensorial/genética , Processamento Alternativo , Áustria , Sequência de Bases , Estudos de Casos e Controles , Conexina 26 , Éxons , Frequência do Gene , Testes Genéticos , Perda Auditiva Neurossensorial/congênito , Perda Auditiva Neurossensorial/diagnóstico , Heterozigoto , Humanos , Programas de Rastreamento , Polimorfismo Genético
3.
Eur Arch Otorhinolaryngol ; 272(1): 229-32, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25085637

RESUMO

The objective of this study was to investigate the relevance of routine assessment of c.-259C>T in the Austrian newborn screening program. Homozygous and compound heterozygous mutations in the coding region of the human gene encoding gap junction protein GJB2 (Connexin 26) cause up to 50 % of neonatal autosomal recessive non-syndromic hearing impairment identified in Caucasian newborn screening programs. More recently, a null mutation in the GC box of the GJB2 basal promoter c.-259C>T has been described which causes hearing impairment by completely suppressing GJB2 promoter activity. We determined the occurrence of c.-259C>T in cases of non-syndromic hearing impairment lacking known pathogenic alterations in GJB2 (n = 43), a non-syndromic hearing impaired patient group (n = 15) bearing the heterozygous GJB2 mutations c.35delG, c.[79G>A];[341A>G] (p. [V27I];[E114G]), c.109G>A (p.V37I), c.154G>C (p.V52L), c.262G>T (p.A88S), c.269T>C (p.L90P) and c.551G>C (p.R184P) and in a normal hearing group lacking alterations in GJB2 (n = 50). In the analyzed groups, no occurrence of c.-259C>T was found. The c.-259C>T mutation, previously described as -3438C>T, is not a common cause of non-syndromic hearing impairment alone or together with heterozygous pathogenic GJB2 mutations that are statistically overrepresented in non-syndromic hearing impaired patient groups. Screening of newborns for c.-259C>T is therefore unlikely to be commonly found in Austrian NSHI patients but could make a significant contribution to non-syndromic hearing impairment in other populations.


Assuntos
Conexinas/genética , DNA/genética , Perda Auditiva/genética , Mutação , Áustria/epidemiologia , Conexina 26 , Conexinas/metabolismo , Feminino , Perda Auditiva/epidemiologia , Humanos , Recém-Nascido , Masculino , Reação em Cadeia da Polimerase , Prevalência , Regiões Promotoras Genéticas
4.
Wien Klin Wochenschr ; 127(11-12): 440-4, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25409950

RESUMO

BACKGROUND: Hearing loss is the most common sensory disorder in developed countries and leads to a severe reduction in quality of life. In this uncontrolled case series, we evaluated the auditory development in patients suffering from congenital nonsyndromic hearing impairment related to preterm birth. METHODS: Six patients delivered preterm (25th-35th gestational weeks) suffering from mild to profound congenital nonsyndromic hearing impairment, descending from healthy, nonconsanguineous parents and were evaluated by otoacoustic emissions, tympanometry, brainstem-evoked response audiometry, and genetic testing. All patients were treated with hearing aids, and one patient required cochlear implantation. RESULTS: One preterm infant (32nd gestational week) initially presented with a 70 dB hearing loss, accompanied by negative otoacoustic emissions and normal tympanometric findings. The patient was treated with hearing aids and displayed a gradual improvement in bilateral hearing that completely normalized by 14 months of age accompanied by the development of otoacoustic emission responses. Conclusions We present here for the first time a fully documented preterm patient with delayed auditory pathway maturation and normalization of hearing within 14 months of birth. Although rare, postpartum development of the auditory system should, therefore, be considered in the initial stages for treating preterm hearing impaired patients.


Assuntos
Correção de Deficiência Auditiva/instrumentação , Correção de Deficiência Auditiva/métodos , Deficiências do Desenvolvimento/diagnóstico , Deficiências do Desenvolvimento/reabilitação , Transtornos da Audição/congênito , Transtornos da Audição/diagnóstico , Feminino , Auxiliares de Audição , Humanos , Lactente , Recém-Nascido , Recém-Nascido Prematuro , Masculino , Resultado do Tratamento
5.
Audiol Neurootol ; 19(3): 203-9, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24801666

RESUMO

Norrie disease is a rare, X-linked genetic syndrome characterized by combined congenital blindness and progressive hearing impairment. Norrie disease is caused by alterations in the NDP gene encoding the growth factor norrin that plays a key role in vascular development and stabilization of the eye, inner ear and brain. We identified a family with 3 affected deafblind males and a single female carrier presenting with a serous retinal detachment but normal hearing. Genetic analysis revealed a novel c.277T>C missense mutation causing the substitution of a hydrophobic cysteine to a hydrophilic arginine [p.(Cys93Arg)] within the highly conserved cysteine knot domain of the norrin protein. These results should expand the scope for amniocentesis and genetic testing for Norrie disease which is gaining in importance due to novel postnatal therapeutic concepts to alleviate the devastating retinal symptoms of Norrie disease.


Assuntos
Cegueira/congênito , Proteínas do Olho/genética , Mutação de Sentido Incorreto , Proteínas do Tecido Nervoso/genética , Doenças do Sistema Nervoso/genética , Espasmos Infantis/genética , Cegueira/genética , Família , Feminino , Doenças Genéticas Ligadas ao Cromossomo X , Testes Genéticos , Humanos , Masculino , Linhagem , Degeneração Retiniana
6.
Int J Pediatr Otorhinolaryngol ; 78(5): 837-42, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24636747

RESUMO

OBJECTIVES: Similar to other zona pellucida mutations in the alpha-tectorin (TECTA) gene, the p.Y1870C alteration in DFNA8/12 causes prelingual, nonsyndromic, autosomal dominant hearing loss. Here we investigated the effect of p.Y1870C on reverse transduction by audiometric studies in the family. METHODS: Pure tone audiometry, brainstem evoked response audiometry, the Freiburger test for speech understanding and transient evoked and distortion product otoacoustic emissions were assessed in three available affected members bearing p.Y1870C. RESULTS: Pure tone audiometry showed U-shaped curves with moderate to severe degrees of hearing impairment confirmed by brainstem evoked response audiometry. Transient evoked and distortion product otoacoustic emissions were completely absent in all affected family members whereas word recognition scores were up to 95%. CONCLUSIONS: Although the missense p.Y1870C TECTA mutation leads to complete failure of the cochlear amplifier in humans, very high speech perception scores can be achieved with appropriate therapy.


Assuntos
Potenciais Evocados Auditivos do Tronco Encefálico/genética , Proteínas da Matriz Extracelular/genética , Perda Auditiva Neurossensorial/diagnóstico , Emissões Otoacústicas Espontâneas/genética , Adulto , Audiometria de Tons Puros/métodos , Áustria , Feminino , Proteínas Ligadas por GPI/genética , Perda Auditiva Neurossensorial/genética , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Mutação de Sentido Incorreto , Linhagem , Percepção da Fala , Adulto Jovem
7.
Otol Neurotol ; 34(4): 650-6, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23640091

RESUMO

HYPOTHESIS: Additional genetic changes in the regulatory region of the human GJB2 gene encoding the gap junction protein (Connexin 26) may contribute to sensorineural hearing loss. BACKGROUND: Mutations in GJB2 cause up to 50% of autosomal recessive nonsyndromic hearing impairment (NSHI). METHODS: In the present study, we screened the putative 5' GJB2 regulatory region for novel alterations. RESULTS: In idiopathic familial cases of NSHI lacking known pathogenic alterations in GJB2, we identified a T→C transition (refSNP: rs117685390) in a putative transcription factor binding sequence 228 bp proximal to the transcriptional start site at a homozygous frequency of 0.125 (n = 40), significantly overrepresented in comparison to the homozygous allele frequencies of 0.043 in the normal-hearing Caucasian population (n = 211; p < 0.001). In a NSHI family, inheritance of the rs117685390 C allele segregated on independent chromosomes with NSHI in conjunction with heterozygous inheritance of c.35delG, the most common Caucasian mutation in the GJB2 coding region. In a patient group (n = 32) bearing heterozygous pathogenic c.35delG mutations, - rs117685390 C allele homozygosity was also highly overrepresented (0.25; p < 0.001) and not exclusively linked to the c.35delG mutation in cis in patients homozygous for c.35delG. However, in the majority of NSHI homozygous c.35delG chromosomes examined (91/94), c.35delG homozygosity was linked to the rs117685390 C allele in cis. CONCLUSION: These results suggest that the rs117685390 C allele could represent a biomarker for the development of NSHI in Caucasian populations and may be included in risk assessment for the development of NSHI.


Assuntos
Conexinas/genética , Perda Auditiva/genética , Polimorfismo de Nucleotídeo Único , Adulto , Alelos , Conexina 26 , Feminino , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Genótipo , Perda Auditiva Neurossensorial/genética , Homozigoto , Humanos , Masculino , Mutação
8.
Laryngoscope ; 122(10): 2300-3, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22777797

RESUMO

In the present article we report an endolymphatic sac tumor in a 15-year-old male who had additional angiomatous lesions in the nasal and pharyngeal mucosa and was diagnosed with von Hippel-Lindau disease postoperatively. Preoperative imaging excluded cholesteatoma, but did not provide sufficient information to distinguish between jugular paraganglioma and endolymphatic sac tumor. To the authors' knowledge this is the first description of angiomatous lesions in the mucosa of the upper respiratory tract in a von Hippel-Lindau disease patient, a potentially useful finding for future radiological differential diagnosis in cases presenting with endolymphatic sac tumor.


Assuntos
Angiomatose/diagnóstico , Neoplasias da Orelha/diagnóstico , Mucosa Nasal/patologia , Doenças Nasais/diagnóstico , Doenças Faríngeas/diagnóstico , Doença de von Hippel-Lindau/diagnóstico , Adolescente , Diagnóstico Diferencial , Saco Endolinfático/diagnóstico por imagem , Saco Endolinfático/patologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Tomografia Computadorizada por Raios X
9.
Laryngoscope ; 120(2): 359-64, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19950373

RESUMO

OBJECTIVES/HYPOTHESIS: Analysis of association between genotype and phenotype. STUDY DESIGN: Prospective genetic study in a family. METHODS: Auditory investigations, computer tomography, and genetic sequencing of the fibroblast growth factor 3 (FGF3) gene were performed on a Somali family presenting with autosomal recessive, hearing impairment, microdontia, and outer ear morphologies ranging from normal auricle development to microtia assessed as type 1 Weerda dysplasia in affected individuals. RESULTS: Computed tomography imaging identified differential inter- and intraindividual malformations of the inner ear including labyrinth aplasia, development of a common cavity to the presence of a cochlear with 1.5 windings (Mondini malformation) in affected individuals, symptoms similar to those described as labyrinth aplasia, microtia, and microdontia (LAMM) syndrome, caused by mutations in FGF3. Genetic sequencing revealed the presence of a novel p.R95W missense mutation in FGF3 segregating with pathology. The p.R95W mutation substitutes a positively charged arginine for a polar tryptophan in the highly conserved RYLAM consensus of the beta 6 sheet of FGF3 that interacts with FGFR2. CONCLUSIONS: These findings describe, for the first time, variable inner ear malformations and outer ear dysplasia in the presence of constant microdontia, associated with homozygous inheritance of the p.R95W mutation in FGF3, mirroring phenotypes observed in mouse models ablating FGF3/FGFR2 signaling.


Assuntos
Anormalidades Múltiplas/genética , Orelha Externa/anormalidades , Orelha Interna/anormalidades , Fator 3 de Crescimento de Fibroblastos/genética , Mutação de Sentido Incorreto , Anormalidades Dentárias/genética , Feminino , Perda Auditiva Neurossensorial/congênito , Perda Auditiva Neurossensorial/genética , Humanos , Masculino , Linhagem
10.
Otol Neurotol ; 28(7): 884-6, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17955603

RESUMO

OBJECTIVE: To analyze the prevalence and importance of the maternally inherited A1555G mutation in the 12S rRNA gene in the Austrian population. STUDY DESIGN: Investigation for mutations of genetically affected familial and sporadic cases of hearing impairment (HI), including analyses of audiometric data. SETTING: Teaching hospital, tertiary referral center. PATIENTS: Forty-five familial and 77 sporadic cases of nonsyndromic HI in an Austrian Caucasian ethnic group. MAIN OUTCOME MEASURE(S): Pure-tone audiometric data and screening by restriction fragment length polymorphism analysis after exclusion of GJB2 (Connexin 26) caused hearing loss. RESULTS: In the investigated hearing-impaired population, the mutation A1555G in the mitochondrial 12S rRNA gene was not detected. CONCLUSION: The A1555G mutation in the mitochondrial DNA 12S rRNA is not a major cause of HI in the Austrian Caucasian population.


Assuntos
Perda Auditiva/epidemiologia , Perda Auditiva/genética , RNA Ribossômico/genética , Audiometria de Tons Puros , Áustria/epidemiologia , Conexina 26 , Conexina 30 , Conexinas/genética , DNA/genética , DNA Mitocondrial/genética , Frequência do Gene , Humanos , Mutação/fisiologia , Polimorfismo de Fragmento de Restrição
11.
Otol Neurotol ; 28(7): 884-886, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17704703

RESUMO

OBJECTIVE:: To analyze the prevalence and importance of the maternally inherited A1555G mutation in the 12S rRNA gene in the Austrian population. STUDY DESIGN:: Investigation for mutations of genetically affected familial and sporadic cases of hearing impairment (HI), including analyses of audiometric data. SETTING:: Teaching hospital, tertiary referral center. PATIENTS:: Forty-five familial and 77 sporadic cases of nonsyndromic HI in an Austrian Caucasian ethnic group. MAIN OUTCOME MEASURE(S):: Pure-tone audiometric data and screening by restriction fragment length polymorphism analysis after exclusion of GJB2 (Connexin 26) caused hearing loss. RESULTS:: In the investigated hearing-impaired population, the mutation A1555G in the mitochondrial 12S rRNA gene was not detected. CONCLUSION:: The A1555G mutation in the mitochondrial DNA 12S rRNA is not a major cause of HI in the Austrian Caucasian population.

12.
Ear Hear ; 28(3): 298-301, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17485979

RESUMO

OBJECTIVES: The aim of the present study was to evaluate gap junction protein beta2 (GJB2) genetic testing within a national neonate screening program for hearing loss (HL) in a European population. DESIGN: Neonatal cases of nonsyndromic HL (N = 21) were identified by postpartal otoacoustic emissions (OAE) and brain stem electric response audiometry (BERA) analysis. GJB2 testing was performed by direct sequencing. RESULTS: Mutations in GJB2 were found in 15 of 21 children (71.4%) identified by neonatal audiological screening. The 35delG mutation in GJB2 was found homozygous in 10 cases (47.6%) and also as a clear cause of HL as the heterozygous alterations 35delG/del311-324 and 35delG/L90P. In a single case, L90P/R143Q was also identified as a cause of HL. In 3 HL cases that were not identifiable during initial OAE testing, homozygous 35delG and 35delG/R184P defined the genetic basis for HL in 2 cases, whereas one case had wild-type GJB2. CONCLUSIONS: Our findings of the high mutation rate in the Austrian population, especially in neonates identified during the newborn screening program, confirm the importance of screening for mutations in GJB2.


Assuntos
Conexinas/genética , Transtornos da Audição/epidemiologia , Transtornos da Audição/genética , Programas de Rastreamento/métodos , Triagem Neonatal , Mutação Puntual/genética , Áustria/epidemiologia , Conexina 26 , Feminino , Transtornos da Audição/diagnóstico , Humanos , Incidência , Recém-Nascido , Masculino
13.
Eur J Hum Genet ; 15(1): 18-22, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17003842

RESUMO

Pulmonary arterial hypertension is a progressive disease, characterised by increased proliferation of pulmonary artery smooth muscle cells, vasoconstriction and remodelling of the vascular wall leading to right heart failure and death. The idiopathic form is rare (idiopathic arterial primary hypertension (IPAH); formerly PPH, MIM# 178600). Our group correlated a deficiency in vasoactive intestinal peptide (VIP; MIM# 192320) levels in serum and lung tissue with the pathogenesis of IPAH. The aim of this study was to investigate the relevance of genetic alterations in VIP to the development of IPAH. We screened 10 patients (age 4-66 years) for alterations in the coding, the noncoding regions and the enhancer region of the VIP gene by direct sequencing. In eight of 10 patients, we found alterations compared to the wild-type sequence. We detected nine alterations. In the noncoding regions, eight alterations were in the introns 1, 2, 3 and 4 (g.448G>A g.501C>T g.764T>C g.2267A>T g.2390C>T g.3144T>C g.3912A>G g.4857A>G). In the coding regions, a single alteration in the 3' untranslated region in exon 7 (g.8129T>C) was observed in five patients. It appeared in 46% of the control group. The frequency of this alteration in the coding region of the VIP gene could therefore not be correlated with the appearance of IPAH. Apart from the importance of VIP signalling, genetic and/or environmental modifiers might therefore contribute to the development and perpetuation of the disease.


Assuntos
Hipertensão Pulmonar/genética , Hipertensão Pulmonar/metabolismo , Peptídeo Intestinal Vasoativo/genética , Peptídeo Intestinal Vasoativo/metabolismo , Regiões 3' não Traduzidas , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Éxons , Feminino , Humanos , Hipertensão Pulmonar/sangue , Íntrons , Masculino , Pessoa de Meia-Idade , Mutação , Análise de Sequência de DNA , Peptídeo Intestinal Vasoativo/sangue
14.
Laryngoscope ; 115(3): 461-5, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15744158

RESUMO

OBJECTIVES/HYPOTHESIS: Hearing impairment has a high prevalence affecting approximately 1 in 1000 newborn children. Alterations in the gap junction protein beta 2 (GJB2) and gap junction protein beta 6 (GJB6) are associated with nonsyndromic hearing impairment and should have a significant impact on genetic counseling. STUDY DESIGN: Various cases of nonsyndromic hearing impairment were screened for alterations in GJB2 and GJB6 in this clinical study. METHODS: The prevalence of mutations in GJB2 encoding for connexin 26 in a patient group with nonsyndromic hearing impairment comprising 45 families and 57 sporadic cases was initially determined by sequencing. The role of GJB2 was then assessed in individuals with hearing impairment (3 families and 20 sporadic cases) who are usually excluded from analysis because of the presence of additional symptoms or in cases in which a role for nongenetic factors cannot be eliminated. In hearing-impaired individuals with heterozygous GJB2 mutations the recently identified 342-kb deletion truncating GJB6 called del(GJB6-D13S1830) as a digenetic component in hearing impairment was excluded by polymerase chain reaction. RESULTS: Autosomal recessively inherited GJB2 mutations induced hearing impairment in 25.5% of individuals in the nonsyndromic hearing impairment group. GJB2 alterations were also seen in 17.4% of individuals in whom additional symptoms or a role for nongenetic involvement could not be excluded. In all, 15 different alterations in GJB2 were detected, including the previously unknown 154G>C, 557C>T, and 682C>T mutations, and these were correlated to clinical parameters. CONCLUSION: Improved genetic counseling can be performed by screening for GJB2 alterations in patients with nonsyndromic hearing impairment including patients within groups for which a role for exogenetic factors cannot be excluded. Specific genetic counseling for GJB2-linked hearing impairment in heterozygotes will depend on future research.


Assuntos
Conexinas/genética , Perda Auditiva/genética , Mutação , Deleção Cromossômica , Conexina 26 , Conexina 30 , Genes Recessivos , Aconselhamento Genético , Perda Auditiva/congênito , Heterozigoto , Humanos , Recém-Nascido , Prevalência , Análise de Sequência de DNA
15.
Hear Res ; 196(1-2): 115-8, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15464308

RESUMO

Genetically caused congenital deafness is a common trait affecting 1 in 2000 newborn children and is predominantly inherited in an autosomal recessive fashion. Genes such as the gap junction protein beta 2 (GJB2) encoding for Connexin (Cx26) and GJB6 (Cx30) are known to cause sensorineural deafness. Autosomal recessive deafness has been linked both to the monogenetic occurrence of mutated GJB2 or the GJB6 deletion del(GJB6-D13S1830) and digenic GJB2/del(GJB6-D13S1830) inheritance. Monogenetic GJB2 alterations are responsible for 25.5% of deafness in the eastern Austrian population. An additional 9.8% are heterozygous carriers of a single GJB2 mutation which is not responsible for deafness alone. Del(GJB6-D13S1830) and GJB2/del(GJB6-D13S1830) mutations have been shown to be the second most frequent cause of deafness in different populations. To address the question of the relevance of mutations in GJB6 either as a monogenetic or a digenic GJB2/del(GJB6-D13S1830) cause of deafness in this population, 76 unrelated individuals (33 families and 43 sporadic cases) were screened using PCR strategies. Similar to studies in other hard of hearing populations with similar or lower carrier frequencies of single GJB2 mutations, the presence of del(GJB6-D13S1830) was not detected in any individual within the patient group. Data therefore exclude a digenetic association of del(GJB6-D13S1830) with heterozygous GJB2 mutations as a cause of deafness in a representative sample of the population from Eastern Austria.


Assuntos
Conexinas/genética , Surdez/genética , Testes Genéticos , Perda Auditiva Neurossensorial/genética , Áustria , Conexina 26 , Conexina 30 , Frequência do Gene , Heterozigoto , Humanos
16.
Hear Res ; 194(1-2): 81-6, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15276679

RESUMO

Mutations in the gap junction protein beta 3 (GJB3) gene encoding Connexin 31 (Cx31) are known to cause autosomal inherited sensorineural deafness, erythrokeratodermia and neuropathy. The role of Cx31 mutations has not been described in familial cases of non-syndromic hearing impairment (NSHI) in central European populations. To identify mutations in the Austrian population, highly selected familial (n=24) and sporadic (n=21) cases of isolated NSHI were screened by analysis of the complete coding sequence of Cx31, after exclusion of a common Cx26 causing deafness. Three different variations occurring in a total of 37% of all cases were identified. A C94T (R32W) missense mutation was seen in 4.4% of cases and two silent alterations C357T and C798T were detected in 8.9% and 24.4% of cases exclusively in a heterozygous pattern. No correlation between Cx31 alterations and deafness was found. To investigate the role of heterozygous Cx31 variations for a possibly combination allelic disease inheritance with Cx26 mutations as shown for Connexin 30 and Connexin 26, patients with Cx26 variations were tested. Our data suggest that Cx31 alterations are common but have no or a low genetic relevance in the Austrian hearing impaired population with or without Cx26 alterations.


Assuntos
Transtornos Cromossômicos/genética , Conexinas/genética , Perda Auditiva Neurossensorial/genética , Mutação Puntual , Áustria , Conexina 26 , Análise Mutacional de DNA , Feminino , Testes Genéticos , Humanos , Masculino , Linhagem , Polimorfismo de Fragmento de Restrição
17.
Audiol Neurootol ; 9(1): 47-50, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-14676473

RESUMO

Mutations in the connexin 26 (Cx26) gene (GJB2) are a common cause of hereditary hearing impairment which affects approximately 1 in 2000 newborn children. We report the identification of a novel Cx26 point mutation (439 G-->A) linked to familial, autosomal recessive, sensorineural hearing loss. This missense mutation (E147K) is located in the highly conserved, putative K(+) channel lining sequence of the third transmembrane domain (TM3) of Cx26. Hearing impairment associated with this mutation was congenital, moderate to profound and showed no signs of progressive deterioration.


Assuntos
Conexinas/genética , Perda Auditiva Neurossensorial/genética , Mutação Puntual/genética , Adolescente , Adulto , Sequência de Aminoácidos , Estudos de Casos e Controles , Criança , Conexina 26 , Feminino , Genes Recessivos , Humanos , Lactente , Masculino , Dados de Sequência Molecular , Mutação de Sentido Incorreto , Linhagem , Polimorfismo de Fragmento de Restrição
18.
Eur J Hum Genet ; 10(7): 427-32, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12107817

RESUMO

Mutations in the connexin 26 (Cx26) gene (GJB2) are associated with autosomal nonsyndromic sensorineural hearing loss. This study describes mutations in the Cx26 gene in cases of familial and sporadic hearing loss (HL) by gene sequencing and identifies the allelic frequency of the most common mutation leading to HL (35delG) in the population of eastern Austria. For this purpose we have developed and applied a molecular beacon based real-time mutation detection assay. Mutation frequencies in the Cx26 gene of individuals from affected families (14 out of 46) and sporadic cases (11 out of 40) were 30.4% and 27.5%, respectively. In addition to known disease related alterations, a novel mutation 262 G-->T (A88S) was also identified. 35delG accounted for almost 77% of all Cx26 mutations detected and displayed an allelic frequency in the normal hearing population of 1.7% (2 out of 120). The high prevalence of the 35delG mutation in eastern Austria would therefore allow screening of individuals and family members with Cx26 dependent deafness by a highly specific and semi-automated method.


Assuntos
Conexinas/genética , Perda Auditiva Neurossensorial/genética , Adolescente , Adulto , Áustria , Criança , Pré-Escolar , Conexina 26 , Frequência do Gene , Humanos , Mutação , Mutação Puntual , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Espectrometria de Fluorescência , Temperatura
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