Whole exome sequencing (WES) is a genomic technique that sequences all the protein-coding regions of genes in a genome, known as the exome. The exome comprises about 1% to 2% of the human genome but contains approximately 85% of known disease-related genetic variants
. This method focuses on sequencing exons—the DNA segments that encode proteins—making it a cost-effective alternative to whole-genome sequencing while still capturing the majority of clinically relevant variants
. WES involves two main steps: first, selectively capturing the exonic DNA from a DNA sample using target-enrichment strategies such as array-based or in-solution hybrid capture; second, sequencing these captured regions using high-throughput DNA sequencing technologies
. This approach enables identification of genetic variants that alter protein sequences, which can cause Mendelian (rare) and common polygenic diseases such as Alzheimer's disease
. Clinically, WES is widely used for diagnosing rare genetic disorders, especially when the causative gene is unknown, by analyzing either all genes or virtual gene panels relevant to the patient’s symptoms
. It is also valuable in research to discover novel disease-causing genes. WES can provide faster results than whole-genome sequencing and is applied in various fields including cancer genetics, population genetics, and neurodegenerative disease diagnostics
. In summary, whole exome sequencing is a powerful and efficient genetic testing method that sequences the protein-coding regions of the genome to identify disease-causing variants, offering a balance between cost, speed, and diagnostic yield
