Objective: To study the SLC26A4 gene mutations in patients with nonsyndromic hearing loss (NSHL) and provide the clinical guidance of gene diagnosis.
Methods: PCR and denaturing high-performance liquid chromatography (DHPLC) were used to screen the 21 exons and their flanking regions of the SLC26A4 gene. Samples with abnormal DHPLC wave patterns were sequenced to identify the variations.
Results: Among the 30 unrelated NSHL patients in whom no deafness-causing mutations of the GJB2 gene were identified, 10 types of variations were detected, including 7 known mutations, 2 novel mutations (F572L and D87Y), and 1 known polymorphism (Ivs11+47T>C). The Ivs7-2A>G is the most common type of variation, accounting for 40% of all the mutations.
Conclusion: SLC26A4 mutation is a major cause of NSHL, just next to the GJB2 mutations. For NSHL patients without deafness-causing GJB2 mutations, the SLC26A4 mutation rate was 23.3%, and the Ivs7-2A>G was the most common mutation.