Application of allele-specific primer extension-based microarray for simultaneous multi-gene mutation screening in patients with non-syndromic hearing loss

Congenital hearing loss (HL) is the most common sensory disorder in humans, affecting one in 1000 infants at birth. A high degree of genetic heterogeneity makes it difficult to screen for mutations in all known deafness genes in clinical applications. We have improved a genotyping microarray using the multiplex PCR-based allele-specific primer extension (ASPE) reaction and applied this method for the genetic diagnosis of congenital HL in Korea. Seven different mutations in the GJB2, SLC26A4 and mitochondrial 12S rRNA genes, which were identified on the basis of a previous study in a Korean population, were selected for the study. These genes were used to evaluate the accuracy of the microarray. The test for validation of the current version of HL genotyping micro-array was fully concordant with the results of DNA sequencing in which 51 subjects with non-syndromic HL were originally genotyped. Furthermore, the blind test of the genotyping microarray detected four different mutations in 10 out of 65 patients, and the accuracy of microarray was calculated as 98% (64/65). Therefore, our results suggest that this HL genotyping microarray will be useful in clinical applications for the genetic diagnosis of HL.