Targeted next-generation sequencing (NGS) is a precise, powerful tool that enables in-depth genomic analysis of diseases and disorders that are driven by somatic or germIine variants, as well as analysis of many infectious diseases.
There are two principle methods for targeted sequencing: amplicon-based sequencing which relies on PCR amplification, and hybridization capture which uses complementary probes to capture target sequences. While each method has unique strengths, both enable the user to focus their sequencing efforts on genomic regions of interest, including coding and/or noncoding regions across the human genome, or in the genomes of model organisms or pathogens.
What advantages does targeted sequencing offer over WGS?
This focused approach yields deeper sequencing of target regions with fewer total reads compared to whole-genome sequencing (WGS), reducing the amount of sequencing needed and the time required for analysis. The greater depth of coverage enabled by targeted NGS increases the accuracy of sequencing data; this is especially important in variant calling in cancer research, identification of rare disease-associated mutations, and analysis of single-gene disorders.
The focused approach of targeted sequencing may also aid the development of targeted therapy applications and personalized medicine. For example, targeted resequencing of the polymorphic human leucocyte antigen (HLA) gene aids in HLA typing, which is crucial for matching in hematopoietic stem cell or solid organ transplantation. These methods can also be rapidly adapted to meet emerging health threats, such as SARS-CoV-2.