Prevalence of the A1555G (12S rRNA) and tRNA Ser(UCN) mitochondrial mutations in hearing-impaired Brazilian patients
Rev. bras. pesqui. méd. biol
; Braz. j. med. biol. res;39(2): 219-226, Feb. 2006. tab, graf
Article
em En
| LILACS
| ID: lil-420273
Biblioteca responsável:
BR1.1
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.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
LILACS
Assunto principal:
RNA Ribossômico
/
RNA de Transferência de Serina
/
Perda Auditiva
/
Mutação
Tipo de estudo:
Observational_studies
/
Prevalence_studies
/
Risk_factors_studies
Limite:
Female
/
Humans
/
Male
País/Região como assunto:
America do sul
/
Brasil
Idioma:
En
Revista:
Braz. j. med. biol. res
/
Rev. bras. pesqui. méd. biol
Assunto da revista:
BIOLOGIA
/
MEDICINA
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Brasil