SLC26A4 c.919-2A>G varies among Chinese ethnic groups as a cause of hearing loss

Abstract

Purpose: Mutations in the SLC26A4 gene are second only to GJB2 mutations as a currently identifiable genetic cause of sensorineural hearing loss. In most areas of China, genetic testing for sensorineural hearing loss is unavailable because of limited knowledge of the mutation spectrum. Although SLC26A4 c.919-2AϾG (IVS7-2AϾG) is a common mutation among some Asian populations, the mutation prevalence among various ethnic groups within China has not been studied. Methods: DNA specimens from 3271 subjects with moderate to profound sensorineural hearing loss from 27 regions of China were genotyped for the c.919-2AϾG mutation by polymerase chain reaction/restriction-fragment-length polymorphism. Normal hearing controls from Han (n ϭ 185) and Uigur (n ϭ 152) populations were also tested. Results: Overall, 408 subjects with sensorineural hearing loss (12.5%) carried at least one c.919-2AϾG allele, with 158 (4.8%) homozygotes and 250 (7.6%) heterozygotes. Within the subpopulations examined, the rate varies from 0% to 12.2% for c.919-2AϾG homozygotes and from 0% to 17.6% for heterozygotes. Based on this cohort, Chinese subjects with sensorineural hearing loss seem to have a relatively

SNPscan as a high-performance screening tool for mutation hotspots of hearing loss-associated genes

“…In subjects with HL in the present study, the 235delC in the GJB2 gene and c.919-2A N G in the SLC26A4 gene were the most common mutations. This prevalence has also been reported by other studies in Chinese population [20,21]. We found that mutations in GJB2 were detected in 42.0% (68/162) of all subjects, whereas the carrier rate of mutations in the SLC26A4 gene was 21.0% (34/162).…”

SLC26A4 mutation spectrum associated with DFNB4 deafness and Pendred's syndrome in Pakistanis

“…8,10,11 p.T416P and IVS8+1G4A are common in Northern Europe, whereas p.H723R and IVS7-2A4G are the most common in East Asia. 8,11,12 We earlier identified mutant alleles of SLC26A4 in 10 (4.7%; 95% CI: 2.6-8.4%) of 212 Pakistani families segregating recessive deafness, which were ascertained through the National Centre of Excellence in Molecular Biology (NCEMB) in Pakistan. 8 p.S90L was the most commonly detected mutation in that initial study.…”

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“…Usami et al (1999) showed that the PDS gene was also responsible for large vestibular aqueduct syndrome (LVAS). There are about 140 types of PDS mutations discovered among patients with PDS or LAVS, with IVS7-2A > G and p.H723R being the most common among East Asia populations (Dai et al, 2008;Pare et al, 2005).…”