What is the difference between Exome Sequencing and Whole Genome Sequencing (WGS)?

Whole Genome Sequencing

• Sequences the complete DNA of an organism, including coding and noncoding nuclear DNA as well as mitochondrial DNA
• Does not require a capture step, which is necessary in exome sequencing
• Can uncover variation in any part of the human genome
• Enables researchers to generate vast quantities of data, which can then be analyzed
• The goal is to look for genetic aberrations such as single nucleotide variants, insertions, and deletions
• Requires more sequencing reagents and generates very large datasets that require sophisticated bioinformatics expertise to decipher, increasing the cost and time required for analysis

Exome Sequencing

• Targets and sequences only coding regions of the genome, referred to as the exome
• Capture-based method
• Exomes can be sequenced at much greater depth (the number of times the nucleotide is sequenced), which provides more confidence in low frequency alterations
• Requires fewer sequencing reagents and generates smaller databases that take less time to perform bioinformatics analysis than whole genome sequencing and is more cost-effective too
• Often used in clinical care to provide greater confidence as well as keep the cost down and provide better opportunity for insurance reimbursement