Determinação da frequencia dos alelos 35delG no gene da conexina 26 em amostras da população brasileira

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

Because of the complexity of the hearing mechanism, deafness can result from a wide variety of genetically determimid anomalies as well as from several environmental factors. In Brazil, the importance of hearing loss among congenital diseases is considerable, since it is present in 2 to 7 per 1,000 births, depending on the studied region. In the last 5 years enormous progress has occurred in localizind and cloning genes associated with inherited hearing loss. Mutations in GJB2 gene, which encode the protein connexin 26, represent a major cause of congenital deafness. This gene is responsible for approximately 80% of the recessive hearing loss. Around 70% of the individuais in different populations with mutations in the GJB2 gene have one specific mutation, namely 35de1G, with a carrier frequency as high as 4% in determined countries. The 35delG carriers frequency was determinated using a method to extract DNAfrom dried-blood filter paper samples obtained from 1,856 newbomsfrom different regions in Brazil. The 35delG mutation was found in 25 individuais (1.35%), wich represent the general frequency of symptom-free 35delG of 1 in 74 births. Besides, the frequency of 35delG carriers depends on the predominant immigration in different regions of the country, particularly from European countries of wich 35delG heterozygous frequency of 1 in 51. The knowledge of 35delGfrequency variation must be useful for genetic counseling and may facilitate an early intervention for a substantial percentage of deaf infants. Due to carriers frequency high of 35delG mutation in Brazil, end the feasibility and benefit of screening for this mutations, it is possible the incorporation of rapid and accurate molecular test appropriate the neonatal screening. Therefore, the investigation of 35delG mutation in neonatal screening for congenital diseases combined with audiologycs tests could be helpful in early identification and management of deafness, wich is important for language development and social skills

ASSUNTO(S)

disturbios da audição conexinas perda auditiva audição

ACESSO AO ARTIGO

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