Our results indicated that the p.V37I exclusive genotype of GJB2 may cause subclinical hearing impairment at birth and increases risk for postnatal PCHI.
Forty-five patients, with sensorineural or mixed HI and an available blood sample for GJB2 sequencing from DNA, were selected from 166 east Greenlanders by specialist audiology examination, including pure-tone air and bone conduction audiometry from 125 Hz to 8000 Hz.
Because of its high frequency, DFNB1hearing impairment has received continued attention from researchers along the years, resulting in a wealth of data that is unparalleled among these disorders.
Our investigations document additional evidence for the correlation between the cited mutations in the GJB2 gene and a syndromic hearing impairment with palmoplantar keratoderma.
A total of 133 children from two deaf and hard of hearing pediatric populations were genotyped first for GJB2/6 and, if negative, then for Usher syndrome.
Audiograms of 62 patients (56 families) with biallelic GJB2 mutations typically indicated a profound hearing loss with T/T mutations, moderate hearing loss with T/NT mutations, and mild hearing impairment with NT/NT mutations (p < 0.01, Student's t test).
This review focuses on the role of connexin 26 and mitochondrial 12S rRNA genes in hearing which will be helpful for better understanding of genes in sporadic and aminoglycoside-induced non syndromic hearing impairment.
We report here on a novel point mutation in GJB2, p.L76P (c.227C>T), in compound heterozygosity with a c.35delG mutation, in two Brazilian sibs, one presenting mild and the other profound nonsyndromic neurosensorial hearing impairment.
Pathogenic mutations in GJB2 and GJB6 genes were detected in 41 individuals (13.7%), and 80.5% (33/41) presented these mutations in homozygosis or compound heterozygosis, thus explaining their hearing defect.
Five SNPs in the DFNB1 region were examined using a case-control association study between cases with sporadic hearing impairment and controls with normal hearing.
One of these probands, however, is also homozygous for the 35delG mutation in the GJB2 gene and a second patient has Down syndrome, which is also associated with hearing impairment.
Although most studies of GJB2 mutations have dealt with hearing-impaired patients, there are few reports of the frequency of these mutations in the general population.