Prevalence of the A1555G (12S rRNA) and tRNA Ser(UCN) mitochondrial mutations in hearing-impaired Brazilian patients
Braz. j. med. biol. res
;
39(2): 219-226, Feb. 2006. tab, graf
Article
Dans Anglais
| LILACS
| ID: lil-420273
RESUMO
Mitochondrial mutations are responsible for at least 1 percent 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 percent), 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 percent (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.
Texte intégral:
Disponible
Indice:
LILAS (Amériques)
Sujet Principal:
ARN ribosomique
/
ARN de transfert de la sérine
/
Perte d'audition
/
Mutation
Type d'étude:
Étude observationnelle
/
Étude de prévalence
/
Facteurs de risque
Limites du sujet:
Femelle
/
Humains
/
Mâle
Pays comme sujet:
Amérique du Sud
/
Brésil
langue:
Anglais
Texte intégral:
Braz. j. med. biol. res
Thème du journal:
Biologie
/
Médicament
Année:
2006
Type:
Article
Pays d'affiliation:
Brésil
Institution/Pays d'affiliation:
Pontifícia Universidade Católica de São Paulo/BR
/
Universidade Estadual de Maringá/BR
/
Universidade de São Paulo/BR
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