Integrated analysis of STRC variants in hereditary hearing impairment using maker-mediated refinement of long-read sequencing with MLPA validation.
TL;DR
The results highlight the diagnostic utility of this combined strategy, integrating LRS with marker-mediated refinements that validated by MLPA assays, in detecting complex STRC variants and advance the understanding of the genetic etiology of SNHI that remains unresolved by conventional NGS approaches.
Abstract
Background
Sensorineural hearing impairment (SNHI) is a common disorder with a significant genetic basis. Standard next-generation sequencing (NGS) often fails to accurately identify pathogenic variants in the STRC gene due to its complex genomic structure, including large rearrangements and a highly homologous pseudogene. Long-read sequencing (LRS) offers improved resolution for these complex regions.
Methods
We developed a comprehensive workflow that integrates PacBio-based LRS with marker-mediated refinements and MLPA validations to specifically address pseudogene interference. This methodology was applied to analyze the STRC gene in a cohort of 100 unrelated Taiwanese patients with SNHI of unknown genetic origin after initial NGS screening.
Results
We identified bi-allelic STRC variants in 11 unrelated patients (11% diagnostic yield), including homozygous deletions, compound heterozygous deletions and conversions, and compound heterozygous single nucleotide variants (SNVs) and copy number variants (CNVs). All unrelated cases resolved with bi-allelic STRC variants were affected with mild or moderate SNHI, occupying 15.1% of total 73 mild-to-moderate SNHI patients in this study.
Conclusion
Our results highlight the diagnostic utility of this combined strategy, integrating LRS with marker-mediated refinements that validated by MLPA assays, in detecting complex STRC variants and advance the understanding of the genetic etiology of SNHI that remains unresolved by conventional NGS approaches.