Evaluation of the presence of the 35delG mutation in patients with severe to profound hearing loss based on ethnicity.

The 35delG mutation in the connexin 26 gene is the most common mutation that generates deafness, but its frequency in different countries is strongly based on its ethnicity. Brazilians belong to different ethnic groups.To report the frequency of homo and heterozygosis 35delG mutation in a population with severe to profound bilateral sensorineural deafness, and separate them by ethnicity.100 individuals were studied with severe to profound hearing loss, with no other etiology found, and tested for 35delG mutation. The group presented the following ethnicity distribution: 25% Blacks; 30% Latin Europeans; 26.2% Blacks/Latin Europeans and 2.3% native.The 35delG mutation was found in 20% of patients: 15% were heterozygous and 5% homozygous. All homozygous were of Latin European origin.Ethnicity shows marked determination of the presence of the 35delG mutation, and it was only found in homozygosis in the group of Latin Europeans.