title: [Analysis of the hereditary etiology of 336 patients with non-syndromic sensorineural hearing loss from Ningxia Hui Autonomous Region of China].
abstract: OBJECTIVE
  To investigate the molecular genetic causes and their characteristics of deafness in Ningxia province, we established screening of three common hereditary deafness genes in 336 deaf and hard-of-hearing patients in this district.
  
  
  METHODS
  Peripheral blood samples were obtained from a total of 336 patients with non-syndromic sensorineural hearing loss in parts of special education schools in Ningxia province to extract genomic DNA. The mitochondrial DNA 12S rRNA m.1555A > G mutation was screened by PCR Alw26I digestion and sequence analysis PCR and direct sequencing were used to analyze the coding region of GJB2 and exons 8 and 19 of SLC26A4. Statistical analysis was performed by using SPSS 11.0 software. Frequencies of different GJB2 or SLC26A4 mutations were compared between Han and Hui people.
  
  
  RESULTS
  Among these 336 patients, seven cases (2.08%, 7/336) were found to carry mtDNA 12S rRNA m.1555A > G homozygous mutation, 45 cases (13.39%) were caused by GJB2 mutations and 28 cases (8.33%) had two mutated alleles (homozygote and compound heterozygote) of SLC26A4. In detail, 16.67% (56/336) patients carried GJB2 mutations including 11 single mutant carriers. The allele frequency of c.235delC and c.299_300delAT were 9.52% (64/672) and 2.68% (18/672), respectively, making up 81.19% (82/101) of all pathogenic mutated alleles for GJB2. The single mutant allele carriers of SLC26A4 is 32, and two types (c.919-2A > G and c.2168A > G) accounted for 95.29% (24/27) mutations, totally. We also found that statistically significant differences in c.919-2A > G and c.2168A > G frequencies between Han and Hui people (c.919-2A > G, χ(2) = 8.229, P = 0.004; c.2168A > G, χ(2) = 5.277, P = 0.022). However, there was no statistically significant difference in GJB2 mutation between Han and Hui people.
  
  
  CONCLUSIONS
  GJB2 mutation was a primary cause for non-syndromic sensorineural hearing loss in Ningxia province, and c.235delC was the most common mutant forms of GJB2. c.919-2A > G and c.2168A > G were common mutant forms of SLC26A4, their frequencies were also statistically significant differences between Han and Hui people.
authors.affiliation: Department of Otorhinolaryngology Head and Neck Surgery, Second Hospital of Lanzhou University, Lanzhou, China.
authors.forename: Yan-li
authors.initials: YL
authors.lastname: Wang
authors.forename: Yi-ming
authors.initials: YM
authors.lastname: Zhu
authors.forename: Xiao-wen
authors.initials: XW
authors.lastname: Liu
authors.forename: Bai-cheng
authors.initials: BC
authors.lastname: Xu
authors.forename: Yu-fen
authors.initials: YF
authors.lastname: Guo
authors.forename: Qiu-ju
authors.initials: QJ
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D044466:Asian People / Q000235:genetics; D002648:Child; D002681:China; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics; D004252:DNA Mutational Analysis; D004272:DNA, Mitochondrial / Q000235:genetics; D005006:Ethnicity / Q000235:genetics; D005260:Female; D005787:Gene Frequency; D006319:Hearing Loss, Sensorineural / Q000209:etiology* / Q000235:genetics*; D006801:Humans; D008297:Male; D026901:Membrane Transport Proteins / Q000235:genetics; D012335:RNA, Ribosomal / Q000235:genetics; D000076988:Sulfate Transporters; D055815:Young Adult
chemical_list: D017630:Connexins; D004272:DNA, Mitochondrial; C000607042:GJB2 protein, human; D026901:Membrane Transport Proteins; D012335:RNA, Ribosomal; C075526:RNA, ribosomal, 12S; C085609:SLC26A4 protein, human; D000076988:Sulfate Transporters; D000072259:Connexin 26