title: SLC26A4 c.919-2A>G varies among Chinese ethnic groups as a cause of hearing loss.
abstract: OBJECTIVE
  Mutations in the SLC26A4 gene are second only to GJB2 mutations as a currently identifiable genetic cause of sensorineural hearing loss. In most areas of China, genetic testing for sensorineural hearing loss is unavailable because of limited knowledge of the mutation spectrum. Although SLC26A4 c.919-2A>G (IVS7-2A>G) is a common mutation among some Asian populations, the mutation prevalence among various ethnic groups within China has not been studied.
  
  
  METHODS
  DNA specimens from 3271 subjects with moderate to profound sensorineural hearing loss from 27 regions of China were genotyped for the c.919-2A>G mutation by polymerase chain reaction/restriction-fragment-length polymorphism. Normal hearing controls from Han (n = 185) and Uigur (n = 152) populations were also tested.
  
  
  RESULTS
  Overall, 408 subjects with sensorineural hearing loss (12.5%) carried at least one c.919-2A>G allele, with 158 (4.8%) homozygotes and 250 (7.6%) heterozygotes. Within the subpopulations examined, the rate varies from 0% to 12.2% for c.919-2A>G homozygotes and from 0% to 17.6% for heterozygotes. Based on this cohort, Chinese subjects with sensorineural hearing loss seem to have a relatively higher c.919-2A>G frequency than that of other Asian populations.
  
  
  CONCLUSIONS
  These results demonstrate that a simple and efficient genetic test for the c.919-2A>G mutation alone would identify the molecular cause in up to 8-12% of individuals with sensorineural hearing loss in a few eastern and central regions of China. Those who are negative for the c.919-2A>G mutation would be candidates for further mutational analysis of SLC26A4 or other deafness-related genes. This would greatly improve genetic diagnosis and counseling for a huge number of Chinese individuals and family members with sensorineural hearing loss in China, and many more ethnic Chinese in other countries, which might be up to one million.
authors.affiliation: Department of Otolaryngology and Genetic Testing Center for Deafness, Chinese PLA General Hospital, Beijing, People's Republic of China.
authors.forename: Pu
authors.initials: P
authors.lastname: Dai
authors.forename: Qi
authors.initials: Q
authors.lastname: Li
authors.forename: Deliang
authors.initials: D
authors.lastname: Huang
authors.forename: Yongyi
authors.initials: Y
authors.lastname: Yuan
authors.forename: Dongyang
authors.initials: D
authors.lastname: Kang
authors.forename: David T
authors.initials: DT
authors.lastname: Miller
authors.forename: Hong
authors.initials: H
authors.lastname: Shao
authors.forename: Qingwen
authors.initials: Q
authors.lastname: Zhu
authors.forename: Jia
authors.initials: J
authors.lastname: He
authors.forename: Fei
authors.initials: F
authors.lastname: Yu
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.forename: Bing
authors.initials: B
authors.lastname: Han
authors.forename: Huijun
authors.initials: H
authors.lastname: Yuan
authors.forename: Orah S
authors.initials: OS
authors.lastname: Platt
authors.forename: Dongyi
authors.initials: D
authors.lastname: Han
authors.forename: Bai-Lin
authors.initials: BL
authors.lastname: Wu
mesh_terms: D000293:Adolescent; D044466:Asian People / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology / Q000208:ethnology; D000072259:Connexin 26; D017630:Connexins; D005260:Female; D005787:Gene Frequency; D014644:Genetic Variation; D005843:Geography; D006319:Hearing Loss, Sensorineural / Q000453:epidemiology / Q000208:ethnology* / Q000235:genetics*; D006801:Humans; D008297:Male; D026901:Membrane Transport Proteins / Q000235:genetics*; D009154:Mutation / Q000235:genetics*; D015995:Prevalence; D000076988:Sulfate Transporters; D055815:Young Adult
chemical_list: D017630:Connexins; C000607042:GJB2 protein, human; D026901:Membrane Transport Proteins; C085609:SLC26A4 protein, human; D000076988:Sulfate Transporters; D000072259:Connexin 26