Background Mutations in GJB2 gene are a major cause of autosomal recessive congenital hearing loss and the cause in some rare cases of the autosomal dominant form The purpose of this study was to investigate the frequ...Background Mutations in GJB2 gene are a major cause of autosomal recessive congenital hearing loss and the cause in some rare cases of the autosomal dominant form The purpose of this study was to investigate the frequency and the features of GJB2 mutations in the Chinese patients with congenital sensorineural deafness Methods Using PCR amplifying the entire coding region of GJB2 gene and direct DNA sequencing to analyze mutations in this gene among unrelated 69 cases with autosomal recessive congenital nonsyndromic deafness and 27 cases of dominant congenital deafness and 35 sporadic cases We also detected mutations in GJB2 in 100 control subjects with normal hearing Results 17 4% (12/69) of the probands in the autosomal recessive, 7 4% (2/27) of dominant families and 5 7% (2/35) of the sporadic congenital deafness patients had deafness causing mutations in GJB2, respectively Nine types of the mutations in GJB2 were detected in the recessive and sporadic group They consisted of five types of polymorphism, and four types of deafness causing mutation with homozygous 35delG in 1 sporadic (1/35), and 235delC frameshift mutation in 1 sporadic (homozygotes) and 10 recessive patients (2 heterozygotes and 8 homozygotes), and homozygous 442G→A missense mutation and homozygous 465T→A nonsense mutation in 1 different recessive proband, respectively The 465T→A that related to recessive deafness was a novel mutation found by this study The homozygous (10/69, 14 5%) and the heterozygous (2/69, 2 9%) GJB2 mutation in the recessive patients (12/69, 17 4%) and the homozygotes in the sporadic patient (2/35, 5 7%) all had congenital severe to profound sensorineural hearing loss 511G→A missense mutation and 299-300delAT frameshift mutation were found in two autosomal dominant congenital deafness families (2/27, 7 4%) The total mutation frequency of GJB2 was 12 2% (16/131) in the Chinese patients with congenital sensorineural deafness and 235delC was the most common deafness causing mutation Six types of mutation—5 types of展开更多
文摘Background Mutations in GJB2 gene are a major cause of autosomal recessive congenital hearing loss and the cause in some rare cases of the autosomal dominant form The purpose of this study was to investigate the frequency and the features of GJB2 mutations in the Chinese patients with congenital sensorineural deafness Methods Using PCR amplifying the entire coding region of GJB2 gene and direct DNA sequencing to analyze mutations in this gene among unrelated 69 cases with autosomal recessive congenital nonsyndromic deafness and 27 cases of dominant congenital deafness and 35 sporadic cases We also detected mutations in GJB2 in 100 control subjects with normal hearing Results 17 4% (12/69) of the probands in the autosomal recessive, 7 4% (2/27) of dominant families and 5 7% (2/35) of the sporadic congenital deafness patients had deafness causing mutations in GJB2, respectively Nine types of the mutations in GJB2 were detected in the recessive and sporadic group They consisted of five types of polymorphism, and four types of deafness causing mutation with homozygous 35delG in 1 sporadic (1/35), and 235delC frameshift mutation in 1 sporadic (homozygotes) and 10 recessive patients (2 heterozygotes and 8 homozygotes), and homozygous 442G→A missense mutation and homozygous 465T→A nonsense mutation in 1 different recessive proband, respectively The 465T→A that related to recessive deafness was a novel mutation found by this study The homozygous (10/69, 14 5%) and the heterozygous (2/69, 2 9%) GJB2 mutation in the recessive patients (12/69, 17 4%) and the homozygotes in the sporadic patient (2/35, 5 7%) all had congenital severe to profound sensorineural hearing loss 511G→A missense mutation and 299-300delAT frameshift mutation were found in two autosomal dominant congenital deafness families (2/27, 7 4%) The total mutation frequency of GJB2 was 12 2% (16/131) in the Chinese patients with congenital sensorineural deafness and 235delC was the most common deafness causing mutation Six types of mutation—5 types of
