<a name="home"></a>Prevalence of the A1555G (12S rRNA) and tRNA Ser(UCN) mitochondrial mutations in hearing-impaired Brazilian patients
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...
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| Format: | Article |
| Language: | English |
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Associação Brasileira de Divulgação Científica
2006-02-01
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| Series: | Brazilian Journal of Medical and Biological Research |
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| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000200008&lng=en&tlng=en |
| _version_ | 1818317930173038592 |
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| author | R.S. Abreu-Silva K. Lezirovitz M.C.C. Braga M. Spinelli S. Pirana V.A. Della-Rosa P.A. Otto R.C. Mingroni-Netto |
| author_facet | R.S. Abreu-Silva K. Lezirovitz M.C.C. Braga M. Spinelli S. Pirana V.A. Della-Rosa P.A. Otto R.C. Mingroni-Netto |
| author_sort | R.S. Abreu-Silva |
| collection | DOAJ |
| description | 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. |
| first_indexed | 2024-12-13T09:45:09Z |
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| institution | Directory Open Access Journal |
| issn | 1414-431X |
| language | English |
| last_indexed | 2024-12-13T09:45:09Z |
| publishDate | 2006-02-01 |
| publisher | Associação Brasileira de Divulgação Científica |
| record_format | Article |
| series | Brazilian Journal of Medical and Biological Research |
| spelling | doaj.art-3efb8292d03240a3875977fe5c14f18b2022-12-21T23:52:05ZengAssociação Brasileira de Divulgação CientíficaBrazilian Journal of Medical and Biological Research1414-431X2006-02-0139221922610.1590/S0100-879X2006000200008S0100-879X2006000200008<a name="home"></a>Prevalence of the A1555G (12S rRNA) and tRNA Ser(UCN) mitochondrial mutations in hearing-impaired Brazilian patientsR.S. Abreu-Silva0K. Lezirovitz1M.C.C. Braga2M. Spinelli3S. Pirana4V.A. Della-Rosa5P.A. Otto6R.C. Mingroni-Netto7Universidade de São PauloUniversidade de São PauloUniversidade Estadual de MaringáPontifícia Universidade Católica de São PauloPontifícia Universidade Católica de São PauloUniversidade Estadual de MaringáUniversidade de São PauloUniversidade de São PauloMitochondrial 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.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000200008&lng=en&tlng=enMitochondrial DNAHearing impairmentA1555G mutationtRNA Ser(UCN) mutationsEuropean- and African- Brazilian patients |
| spellingShingle | R.S. Abreu-Silva K. Lezirovitz M.C.C. Braga M. Spinelli S. Pirana V.A. Della-Rosa P.A. Otto R.C. Mingroni-Netto <a name="home"></a>Prevalence of the A1555G (12S rRNA) and tRNA Ser(UCN) mitochondrial mutations in hearing-impaired Brazilian patients Brazilian Journal of Medical and Biological Research Mitochondrial DNA Hearing impairment A1555G mutation tRNA Ser(UCN) mutations European- and African- Brazilian patients |
| title | <a name="home"></a>Prevalence of the A1555G (12S rRNA) and tRNA Ser(UCN) mitochondrial mutations in hearing-impaired Brazilian patients |
| title_full | <a name="home"></a>Prevalence of the A1555G (12S rRNA) and tRNA Ser(UCN) mitochondrial mutations in hearing-impaired Brazilian patients |
| title_fullStr | <a name="home"></a>Prevalence of the A1555G (12S rRNA) and tRNA Ser(UCN) mitochondrial mutations in hearing-impaired Brazilian patients |
| title_full_unstemmed | <a name="home"></a>Prevalence of the A1555G (12S rRNA) and tRNA Ser(UCN) mitochondrial mutations in hearing-impaired Brazilian patients |
| title_short | <a name="home"></a>Prevalence of the A1555G (12S rRNA) and tRNA Ser(UCN) mitochondrial mutations in hearing-impaired Brazilian patients |
| title_sort | a name home a prevalence of the a1555g 12s rrna and trna ser ucn mitochondrial mutations in hearing impaired brazilian patients |
| topic | Mitochondrial DNA Hearing impairment A1555G mutation tRNA Ser(UCN) mutations European- and African- Brazilian patients |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000200008&lng=en&tlng=en |
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