GJB2 and GJB6 genes mutations in children with non-syndromic hearing loss

Abstract

Introduction. At the moment there is not enough data in

Audiological features in Serbian patients with hearing impairment identified with c.35delG in the GJB2 gene

“…Among the patients eleven exhibited a profound degree of hearing loss with over Only two patients exhibited moderately severe degree of hearing impairment with ~60dB. Our results are in agreement with many published studies worldwide [18,19,25,26]. In general, the majority of homozygotes for the c.35delG exhibit severe to profound hearing impairment, while in a few rare cases develop moderate to even mild hearing impairment [2,3,7,8].…”

“…In the present study, the total frequency of the c.35delG mutant allele was estimated at 30.43% (56/184 alleles) and was identified in 37 patients either in homozygote or heterozygote state (40.22%) (Table 2). The recovered numbers concerning homozygosity and/or heterozygosity of the c35delG are quite similar to the ones previously reported in neighboring populations [10,[18][19][20][21][22][23][24] (Table 3).…”

“…In the group 2 of the present study were allocated 4 patients (4.35% of total cohort) with the compound heterozygous genotype, all of them demonstrated profound hearing loss (Table 2). Similar results were also found in compound heterozygotes from Romanian and Croatian populations identified in 4.8% and 7.9% of total cohort (respectively), who mostly exhibited profound degree of hearing impairment [18,19].…”

Do we really need genetic tests in current clinical practice?

“…analysis is a simple method used to identify single base pair mutations. Nested PCR and ARMS-PCR were routinely used for investigation of c.35delG and pW24X mutations in GJB2 gene 179 children with non-syndromic hearing loss (NSHL) (13). Multiplex-PCR technique is a fast method that allows simultaneous amplification of different DNA sequences (targets) in a single PCR tube.…”

“…Multiplex-PCR may be used for SNP genotyping, mutation analysis, gene deletion analysis. For example it was applied for detection of del(GJB6-D13S1830) and del(GJB6-D13S1854) in GJB6 gene in 179 Romanian NSHL children (13). Reverse transcriptase polymerase chain reaction (RT-PCR) is used to detect the level of RNA transcripts.…”