title: Screening for the GJB2 c.-3170 G>A (IVS 1+1 G>A) mutation in Brazilian deaf individuals using multiplex ligation-dependent probe amplification.
abstract: Mutations in GJB2 gene are the most common cause of nonsyndromic sensorineural recessive hearing loss. One specific mutation, c.35delG, is the most frequent in the majority of Caucasian populations and may account for up to 70% of all GJB2 mutations. However, 10-40% of the patients carry only one pathogenic mutation in the GJB2 gene. Deletions del(GJB6-D13S1830) and del(GJB6-D13S1854), truncating the GJB6 gene, have been detected in GJB2 heterozygous patients in different populations. The IVS 1+1 G>A splice site mutation in the noncoding region of the GJB2 gene has been found in heterozygous state in addition to c.35delG mutation. This mutation has not been reported in Brazilian deaf patients. In the present study we investigated the presence of the IVS 1+1 G>A mutation by multiplex ligation-dependent probe amplification in 185 unrelated Brazilian patients with autosomal recessive nonsyndromic sensorineural hearing loss (43 heterozygous patients and 142 without any pathogenic mutation in the GJB2-coding region). We have found two patients (4.6%) carrying the IVS 1+1 G>A mutation in compound heterozygous with c.35delG mutation.
authors.affiliation: Laboratório de Genética Molecular Humana, Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, Campinas, Brazil.
authors.forename: Sueli Matilde
authors.initials: SM
authors.lastname: da Silva-Costa
authors.forename: Fernanda Borchers
authors.initials: FB
authors.lastname: Coeli
authors.forename: Carolina Rodrigues
authors.initials: CR
authors.lastname: Lincoln-de-Carvalho
authors.forename: Antonia Paula
authors.initials: AP
authors.lastname: Marques-de-Faria
authors.forename: Maurício
authors.initials: M
authors.lastname: Kurc
authors.forename: Tânia
authors.initials: T
authors.lastname: Pereira
authors.forename: Mariza Cavenaghi Argentino
authors.initials: MC
authors.lastname: Pomilio
authors.forename: Edi Lúcia
authors.initials: EL
authors.lastname: Sartorato
mesh_terms: D001938:Brazil; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D003638:Deafness / Q000175:diagnosis* / Q000235:genetics; D006801:Humans; D008403:Mass Screening / Q000379:methods*; D015335:Molecular Probes; D009154:Mutation; D016133:Polymerase Chain Reaction / Q000379:methods*
chemical_list: D017630:Connexins; C000607042:GJB2 protein, human; D015335:Molecular Probes; D000072259:Connexin 26