title: Mutation spectrum of autosomal recessive non-syndromic hearing loss in central Iran.
abstract: OBJECTIVE
  To identify the spectrum of mutations in connexin 26 gene and frequency of two deletions in connexin 30 gene in central Iran.
  
  
  METHODS
  After extraction of DNA from 300 blood samples, connexin 26 gene coding region was amplified using specific primers. PCR products were used for bidirectional sequencing. Multiplex PCR was used for detection of del(GJB6-D13S1830) and del(GJB6-D13S1854) in the GJB6 gene.
  
  
  RESULTS
  Eighteen different mutations including two novel variants in GJB2 gene were detected. The GJB2 mutations were observed in 23.3% of all the subjects. In addition, none of the deaf patients carried the del(GJB6-D13S1830) and del(GJB6-D13S1854) in the GJB6 gene. The 35delG mutation was the most common mutation, accounting for 32.65% of the mutant alleles.
  
  
  CONCLUSIONS
  The present study indicates that mutations in the GJB2 gene particularly 35delG are important causes for ARNSHL. 60% of the patients were heterozygous carriers. Thus, further investigation is needed to detect the genetic cause of hearing loss in patients with mono allelic mutations in the coding region of GJB2.
authors.affiliation: Medical Genetics Laboratory, Alzahra University Hospital, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Asieh
authors.initials: A
authors.lastname: Haghighat-Nia
authors.affiliation: Medical Genetics Laboratory, Alzahra University Hospital, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Azadeh
authors.initials: A
authors.lastname: Keivani
authors.affiliation: Medical Genetics Laboratory, Alzahra University Hospital, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Zakiye
authors.initials: Z
authors.lastname: Nadeali
authors.affiliation: Medical Genetics Laboratory, Alzahra University Hospital, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Esmat
authors.initials: E
authors.lastname: Fazel-Najafabadi
authors.affiliation: Medical Genetics Laboratory, Alzahra University Hospital, Isfahan University of Medical Sciences, Isfahan, Iran; Department of Medical Genetics, School of Medicine, Tehran University of Medical Science, Tehran, Iran.
authors.forename: Majid
authors.initials: M
authors.lastname: Hosseinzadeh
authors.affiliation: Medical Genetics Laboratory, Alzahra University Hospital, Isfahan University of Medical Sciences, Isfahan, Iran; Division of Genetics and Molecular Biology, Medical School, Isfahan University of Medical Sciences, Isfahan, Iran. Electronic address: m_salehi@med.mui.ac.ir.
authors.forename: Mansoor
authors.initials: M
authors.lastname: Salehi
mesh_terms: D000293:Adolescent; D000328:Adult; D000483:Alleles; D000072259:Connexin 26; D000075302:Connexin 30; D017630:Connexins / Q000235:genetics*; D005260:Female; D034381:Hearing Loss / Q000175:diagnosis / Q000235:genetics*; D006579:Heterozygote; D006801:Humans; D007492:Iran; D008297:Male; D009154:Mutation / Q000235:genetics*; D016133:Polymerase Chain Reaction
chemical_list: D000075302:Connexin 30; D017630:Connexins; C000607042:GJB2 protein, human; C491020:GJB6 protein, human; D000072259:Connexin 26
keywords: ARNSHL; Central Iran; GJB2 gene; GJB6 gene