title: Low frequency of GJB2 mutations in thirty-five students with hearing loss in Chinese consanguineous families.
abstract: OBJECTIVE
  GJB2 mutation is recognized as the prevalent causes of non-syndromic hearing impairment (NSHI) worldwide. However, the mutation profiles of this gene are unknown in deafness probands in the consanguineous pedigrees in China. Therefore, this study aimed to characterize the forms and frequencies of GJB2 mutations in 35 students with hearing loss in the consanguineous families in Hubei province, Central China.
  
  
  METHODS
  Genomic DNA was extracted from blood samples of 35 students with hearing loss. The target fragments were amplified by polymerase chain reaction (PCR) and subjected to sequencing to identify sequence variations.
  
  
  RESULTS
  Surprisingly, none of these probands harbored homozygous mutation in GJB2. Three GJB2 heterozygous mutations were identified: a single base pair substitution c.35G>T and c.139G>T, and a 2 bp deletion c.299-300delAT in three probands.
  
  
  CONCLUSIONS
  The frequency of GJB2 mutation is relatively low in these consanguineous families, most of which were minorities. Our results suggest that screening for responsible genes other than GJB2 may be necessary for NSHI in these minorities.
authors.affiliation: Department of Otolarygology, Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Guanming
authors.initials: G
authors.lastname: Chen
authors.forename: Siqing
authors.initials: S
authors.lastname: Fu
authors.forename: Jiashu
authors.initials: J
authors.lastname: Dong
authors.forename: Peiwei
authors.initials: P
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D002648:Child; D002681:China / Q000453:epidemiology; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D003241:Consanguinity; D005260:Female; D034381:Hearing Loss / Q000453:epidemiology / Q000235:genetics*; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D008297:Male; D009154:Mutation; D016133:Polymerase Chain Reaction; D055815:Young Adult
chemical_list: D017630:Connexins; C000607042:GJB2 protein, human; D000072259:Connexin 26