Simultaneous multi-gene mutation screening using SNPscan in patients from ethnic minorities with nonsyndromic hearing-impairment in Northwest China

The present study aimed to investigate the molecular etiology of nonsyndromic hearing impairment (HI) in hearing impaired populations of Hui, Tibetan, and Tu ethnicities in northwest China. A total of 283 unrelated subjects with HI who attended special education schools in northwest China were enrolled in the present study. Single-nucleotide polymorphisms (SNPs) in three common deafness-related genes, gap junction protein β2 (GJB2), solute carrier family 26 member 4 (SLC26A4) and mitochondrially encoded 12S RNA (mtDNA12SrRNA), were detected using a SNPscan technique. GJB2 mutations were detected in 14.89% of Hui patients, 9.37% of Tibetan patients and 11.83% of Tu patients. The most prevalent GJB2 mutation in the Hui and Tu patients was c.235delC. In the Tibetan patients, the c.109G>A SNP exhibited the highest allele frequency. SLC26A4 mutations were detected in 10.64% of Hui patients, 6.25% of Tibetan patients, and 8.6% of Tu patients. The most common SLC26A4 mutation was c.919-2A>Gin the Hui, Tibetan, and Tu patients, and the second most common SLC26A4 mutations in these patients were c.1517T>G, c.1226G>A andc.2168A>G, respectively. The mutation rates ofmtDNA12SrRNA in the Hui, Tibetan, and Tu patients were 1.06, 5.21, and 5.38%, respectively. These findings demonstrate that the mutation spectra of these deafness-related genes are unique amongst these three ethnic groups. This information will be helpful in designing a protocol for genetic testing for deafness and for achieving accurate molecular diagnoses in northwest China.