Hereditary Sensorineural Hearing Loss of Unknown Cause Involving Mitochondrial DNA 1555 Mutation

Iwasaki, Satoshi; Tamagawa, Yuya; Ocho, Shuji; Hoshino, Tomoyuki; Kitamura, Ken

doi:10.1159/000027725

Cited by 18 publications

(13 citation statements)

References 13 publications

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“…Interestingly, the HI phenotype appeared to be more variable in the fourth generation. The variation of the phenotypes in the present pedigree conforms to that in previous studies, where both affected and nonaffected subjects have been found in sibships [Jaber et al, 1992;Usami et al, 1997;Iwasaki et al, 2000;Matsunaga et al, 2004Matsunaga et al, , 2005. However, our findings also differ from previous studies.…”

Section: Phenotype and Penetrancesupporting

confidence: 87%

Audiological Follow-Up of Children with the m.1555A>G Mutation in Mitochondrial DNA

Häkli

Luotonen²,

Sorri³

et al. 2012

Audiol Neurotol

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The age at onset and the severity of hearing impairment (HI) varies widely among subjects and within families with the m.1555A>G mutation in mitochondrial DNA. We examined prospectively the hearing of 19 children in three nuclear families of a pedigree with m.1555A>G during a period of 7.8 years. The children underwent an audiological examination annually. At the end of the follow-up, the children were 2–13 years old. The parents were asked about the exposure of the children to risk factors of HI. We found that the 19 children with m.1555A>G were born with normal hearing and that 10 of them had developed HI by the end of the follow-up. High frequencies were affected first. The median age at the onset of HI was 3.7 years. Both the severity of HI and the age of onset varied within and between families. Most commonly, audiograms revealed a sensorineural, progressive HI sloping towards high frequencies. We could not identify environmental factors which could modify the development of HI. In conclusion, we were able to pinpoint the time of onset of HI and to follow the progression of HI in childhood. Our results show that there are distinct phenotypes, but at present there are no means to predict which phenotype will develop. It is important to follow up the hearing of children in families with the m.1555A>G mutation, because these children generally pass the newborn hearing screening, and the age at onset or the phenotype of HI cannot be predicted.

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Section: Phenotype and Penetrancesupporting

confidence: 87%

Audiological Follow-Up of Children with the m.1555A>G Mutation in Mitochondrial DNA

Häkli

Luotonen²,

Sorri³

et al. 2012

Audiol Neurotol

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“…Samples were screened for two common deletions affecting GJB6 [del(GJB6D13S1830), del(GJB6D13S1854)] and the m.1555A>G mutation in the mitochondrially encoded 12S rRNA gene MT-RNR1 as previously described (20)(21)(22). The entire coding region of GJB2 (exon 2) and the 20 coding exons of SLC26A4 were amplified by polymerase chain reaction (PCR) using primers reported in Supplementary Table S1 and by Everett et al (1), respec tively.…”

Section: Genomic Dna Analysismentioning

confidence: 99%

Reduction of Cellular Expression Levels Is a Common Feature of Functionally Affected Pendrin (SLC26A4) Protein Variants

Moraes

Bernardinelli

Zocal

et al. 2016

Mol Med

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“…In order to screen the del(GJB6-D13S1830) and del(GJB6-D13S1754) mutations, we followed the procedure described by Del Castillo et al [2002,2005]. Additionally, mtDNA A1555G and A7445G mutation detection is carried out as described by Friedman et al [1999] and Iwasaki et al [2000]. The PCR products were digested with specific restriction enzymes, BsmAI for A1555G mutation and XbaI for A7445 mutation, according to the manufacturer's recommended digestion condition.…”

Section: Molecular Genetic Analysismentioning

confidence: 99%

Molecular genetics study of deafness in Brazil: 8‐year experience

Oliveira

Alexandrino

Christiani

et al. 2007

American J of Med Genetics Pt A

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Hereditary hearing loss is a complex disorder that involves a large number of genes. In developed countries, 1 in 1,000 children is born with deafness severe enough to require special education services, and about 60% of the cases of isolated deafness have a genetic origin. Although more than 100 genes for hearing loss are known currently, only a few are routinely tested in the clinical practice. In this study, we present our findings from the molecular diagnostic screening of the GJB2 and GJB3 genes, del(GJB6-D13S1,830) and del(GJB6-D13S1,854) deletions in the GJB6 gene, Q829X mutation in the otoferlin gene (OTOF) and, the A1,555G and A7,445G mutations in the mitochondrial genome over an 8-year period. Mutations analysis in the previously mentioned genes and mutations was performed on 645 unrelated Brazilian patients with hearing loss who fell into two different testing groups. Different mutations in the GJB2 gene were responsible for most of cases studied, but deletions in the GJB6 gene as well as mitochondrial mutations were also found. While most cases of hearing loss in this country are due to environmental factors, the genetic etiology of deafness will increasingly be determined as more genetic tests become available.

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Hereditary Sensorineural Hearing Loss of Unknown Cause Involving Mitochondrial DNA 1555 Mutation

Cited by 18 publications

References 13 publications

Audiological Follow-Up of Children with the m.1555A>G Mutation in Mitochondrial DNA

Audiological Follow-Up of Children with the m.1555A>G Mutation in Mitochondrial DNA

Reduction of Cellular Expression Levels Is a Common Feature of Functionally Affected Pendrin (SLC26A4) Protein Variants

Molecular genetics study of deafness in Brazil: 8‐year experience

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