title: [Analysis of genotype-phenotype correlation for GJB2 in 221 non-syndromic deafness probands and their pedigrees].
abstract: OBJECTIVE
  To assess the possible genotype-phenotype correlation for GJB2.
  
  
  METHODS
  Retrospectively analyzed GJB2 gene mutations with non-syndromic hearing impairment (NSHI) patients and their families audiological data. Individuals were grouped, according to non-truncated mutant (non-truncating, NT) and truncating mutations (truncating, T), into T/T group, T/NT group and NT/NT group. And according to whether they carry 235delC, grouped into 235delC/235delC group, 235delC/Non-235del group and Non-235delC/Non-235delC group.
  
  
  RESULTS
  Grouped according to whether the truncation mutants:Fisher exact statistical analysis showed that the degree of hearing loss among the three groups did not meet the random distribution (P = 0.003) , T/T group was significantly higher than T/NT group (P = 0.000) and NT/NT group (P = 0.000) on the degree of hearing loss. Grouped according to whether they carry 235delC mutation: degrees of hearing loss among the three groups were statistically significant differences. Respectively pairwise comparisons (Fisher exact test) found 235delC/235delC group was significantly higher than 235delC/Non-235delC on the degree of hearing loss group (P = 0.001) and Non-235delC/Non-235delC group (P = 0.000), 235delC/Non-235delC group higher than Non-235delC/Non-235delC group (P = 0.033). In GJB2 mutations homozygous and compound heterozygous mutation genotype:G109A/G109A, 235delC/512insAACG, 299delAT/G109A and 235delC/G109A degree of hearing loss caused by genotype was significantly lower than 235delC/235delC group.
  
  
  CONCLUSIONS
  235delC homozygotes have significantly more hearing impairment, when compared with 235delC/non-235delC compound heterozygotes. People with two non-235delC mutations have even less hearing impairment. Patients with non-truncation mutants (G109A) suffer from lighter hearing loss than truncation mutations(235delC, 299delAT).
authors: Department of Otorhinolaryngology, Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical College, Wenzhou 325027, China.
authors: Xiao
authors: X
authors: Yu
authors: Email: wzbobei@126.com.
authors: Bo-bei
authors: BB
authors: Chen
authors: Hai-jie
authors: HJ
authors: Xiang
authors: Ben-yu
authors: BY
authors: Nan
authors: Jing
authors: J
authors: Zheng
authors: Chu-qin
authors: CQ
authors: Zhang
authors: Jin-jian
authors: JJ
authors: Gao
authors: Bin-jiao
authors: BJ
authors: Zheng
authors: Ying-ying
authors: YY
authors: Chen
authors: Min-xin
authors: MX
authors: Guan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D003638:Deafness / Q000235:genetics; D005838:Genotype; D006579:Heterozygote; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008875:Middle Aged; D009154:Mutation; D010375:Pedigree; D055815:Young Adult
chemical_list: D017630:Connexins; C000607042:GJB2 protein, human; D000072259:Connexin 26