Mutation A1555G in the 12S rRNA gene and its epidemiological importance in German, Hungarian, and Polish patients

Kupka, Susan; Tóth, Tímea; Wróbel, Maciej; Zeißler, Ulrike; Szyfter, Witold; Szyfter, Krzysztof; Niedzielska, G; Bal, Jerzy; Zenner, H. P.; Sziklai, István; Blin, Nikolaus; Pfister, Markus

doi:10.1002/humu.9017

Cited by 82 publications

(41 citation statements)

References 18 publications

(13 reference statements)

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“…The majority of our 203 probands had prelingual deafness, a feature also found in some European studies (19)(20)(21) that reported A1555G frequencies ranging from 0 and 2.4%. If 35delG homozygotes and heterozygotes (the most prevalent connexin 26 mutation) are excluded from our sample (N = 26), the proportion of A1555G is 4/177 (2.25%).…”

Section: Discussionsupporting

confidence: 80%

<a name="home"></a>Prevalence of the A1555G (12S rRNA) and tRNA Ser(UCN) mitochondrial mutations in hearing-impaired Brazilian patients

Abreu-Silva

Lezirovitz

Braga

et al. 2006

Braz J Med Biol Res

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Mitochondrial mutations are responsible for at least 1% of the cases of hereditary deafness, but the contribution of each mutation has not yet been defined in African-derived or native American genetic backgrounds. A total of 203 unselected hearing-impaired patients were screened for the presence of the mitochondrial mutation A1555G in the 12S rRNA gene and mutations in the tRNA Ser(UCN) gene in order to assess their frequency in the ethnically admixed Brazilian population. We found four individuals with A1555G mutation (2%), which is a frequency similar to those reported for European-derived populations in unselected samples. On the other hand, complete sequencing of the tRNA Ser(UCN) did not reveal reported pathogenic substitutions, namely A7445G, 7472insC, T7510C, or T7511C. Instead, other rare substitutions were found such as T1291C, A7569G, and G7444A. To evaluate the significance of these findings, 110 "European-Brazilians" and 190 "African-Brazilians" unrelated hearing controls were screened. The T1291C, A7569G and G7444A substitutions were each found in about 1% (2/190) of individuals of African ancestry, suggesting that they are probably polymorphic. Our results indicate that screening for the A1555G mutation is recommended among all Brazilian deaf patients, while testing for mutations in the tRNA Ser(UCN) gene should be considered only when other frequent deafness-causing mutations have been excluded or in the presence of a maternal transmission pattern.

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Section: Discussionsupporting

confidence: 80%

<a name="home"></a>Prevalence of the A1555G (12S rRNA) and tRNA Ser(UCN) mitochondrial mutations in hearing-impaired Brazilian patients

Abreu-Silva

Lezirovitz

Braga

et al. 2006

Braz J Med Biol Res

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“…Frequency of A1555G among patients with progressive, postlingual hearing impairment Our findings are in line with most other reports of the frequency of A1555G among Europeans with familial hearing impairment, 21,38,39 but strikingly different from studies conducted in Spain, where A1555G has been found at a much higher frequency, up to B25% of individuals with late-onset, familial, progressive hearing impairment. 40 -42 Since such studies have been carried out in more than one laboratory, it is unlikely that they are due to any systematic bias in the collection of subjects.…”

Section: Heteroplasmy For 7472inscsupporting

confidence: 85%

Mitochondrial DNA mutations in patients with postlingual, nonsyndromic hearing impairment

et al. 2004

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Mitochondrial mutations have previously been reported anecdotally in families with maternally inherited, nonsyndromic hearing impairment. To ascertain the contribution of mitochondrial mutations to postlingual but early-onset, nonsyndromic hearing impairment, we screened patients collected from within two different populations (southern Italy and UK) for previously reported mtDNA mutations associated with hearing disorders. Primer extension (SNP analysis) was used to screen for specific mutations, revealing cases of heteroplasmy and its extent. The most frequently implicated tRNA genes, Leu(UUR) and Ser(UCN), were also sequenced in all Italian patients. All tRNA genes were sequenced in those UK patients showing the clearest likelihood of maternal inheritance. Causative mtDNA mutations were found in approximately 5% of patients in both populations, representing almost 10% of cases that were clearly familial. Age of onset, where known, was generally before adulthood, and hearing loss was typically progressive. Haplogroup analysis revealed a possible excess of haplogroup cluster HV in the patients, compared with population controls, but of borderline statistical significance. In contrast, we did not find any of the previously reported mtDNA mutations, nor a significant deviation from haplogroup cluster frequencies typical of the control population, in patients with late adult-onset hearing loss (age-related hearing impairment) from the UK or Finland.

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“…It is probably the most common mtDNA mutation causing hearing loss as it is present in 0.5 to 1% of hearingimpaired Caucasians [25,26], although a much higher prevalence has been reported among Spanish [27] and Asian [28] patients. The A1555G mutation has been found in many families with maternally inherited, nonsyndromic hearing loss, and also in sporadic patients with hearing loss after the use of aminoglycosides.…”

Section: Discussionmentioning

confidence: 99%

Detection of Deafness-Causing Mutations in the Greek Mitochondrial Genome

et al. 2011

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Abstract. Mitochondrion harbors its own DNA, known as mtDNA, encoding certain essential components of the mitochondrial respiratory chain and protein synthesis apparatus. mtDNA mutations have an impact on cellular ATP production and many of them are undoubtedly a factor that contributes to sensorineural deafness, including both syndromic and non-syndromic forms. Hot spot regions for deafness mutations are the MTRNR1 gene, encoding the 12S rRNA, the MTTS1 gene, encoding the tRNA for Ser (UCN) , and the MTTL1 gene, encoding the tRNA for Leu (UUR) . We investigated the impact of mtDNA mutations in the Greek hearing impaired population, by testing a cohort of 513 patients suffering from childhood onset prelingual or postlingual, bilateral, sensorineural, syndromic or non-syndromic hearing loss of any degree for six mitochondrial variants previously associated with deafness. Screening involved the MTRNR1 961delT/insC and A1555G mutations, the MTTL1 A3243G mutation, and the MTTS1 A7445G, 7472insC and T7510C mutations. Although two patients were tested positive for the A1555G mutation, we failed to identify any subject carrying the 961delT/insC, A3243G, A7445G, 7472insC, or T7510C mutations. Our findings strongly support our previously raised conclusion that mtDNA mutations are not a major risk factor for sensorineural deafness in the Greek population.

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Mutation A1555G in the 12S rRNA gene and its epidemiological importance in German, Hungarian, and Polish patients

Cited by 82 publications

References 18 publications

<a name="home"></a>Prevalence of the A1555G (12S rRNA) and tRNA Ser(UCN) mitochondrial mutations in hearing-impaired Brazilian patients

<a name="home"></a>Prevalence of the A1555G (12S rRNA) and tRNA Ser(UCN) mitochondrial mutations in hearing-impaired Brazilian patients

Mitochondrial DNA mutations in patients with postlingual, nonsyndromic hearing impairment

Detection of Deafness-Causing Mutations in the Greek Mitochondrial Genome

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