Prevalence of 35delG/GJB2 and del (GJB6-D13S1830) mutations in patients with non-syndromic deafness from a population of Espírito Santo-Brazil.
Mutations in GJB2 gene are the leading cause of deafness in autosomal recessive inheritance, and the 35delG mutation is the most common in many ethnic groups. Besides the 35delG mutation in homozygosis, the mutation is also found in compound heterozygosis, coupled with other mutations in genes GJB2 and GJB6.


OBJECTIVE
To determine the prevalence of 35delG/GJB2 and del (GJB6-D13S1830) mutations in patients with sensorineural hearing impairment in residents from the Espirito Santo state, Brazil.


METHODS
77 unrelated individuals with moderate to profound sensorineural hearing loss were evaluated. The 35delG mutation was studied by PCR / RFLP; and the del (GJB6-D13S1830) mutation was screened by the technique of multiplex PCR.


RESULTS
88.3% had normal genotype for the studied mutations, 1.3% were compound heterozygotes, 3.9% homozygotic for the 35delG mutation, 6.5% heterozygotic for 35delG/GJB2. The frequency of 35delG/GJB2 and del (D13S1830/GJB6) alleles in the sample was 7.8% and 0.65%, respectively.


CONCLUSIONS
The data confirmed the existence of the mutations studied in cases of sensorineural hearing loss in a population from Espírito Santo / Brazil. These findings reinforce the importance of genetic diagnosis, which can provide early treatment for children and genetic counseling for the affected families.
Cordeiro-Silva
Melissa de Freitas
Mde F
Sao Pedro Integrated Faculties (Faculdades Integradas São Pedro), AEV/FAESA. melissasilva@aev.edu.br
Barbosa
Andressa
A
Santiago
Marília
M
Provetti
Mariana
M
Rabbi-Bortolini
Eliete
E
D000293:Adolescent; D000328:Adult; D001938:Brazil; D002648:Child; D002675:Child, Preschool; D000072259:Connexin 26; D000075302:Connexin 30; D017630:Connexins / Q000235:genetics*; D003430:Cross-Sectional Studies; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006319:Hearing Loss, Sensorineural / Q000235:genetics*; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D015995:Prevalence; D012720:Severity of Illness Index; D055815:Young Adult
D000075302:Connexin 30; D017630:Connexins; C000607042:GJB2 protein, human; C491020:GJB6 protein, human; D000072259:Connexin 26