What is the Difference Between Genome and Exome?

The main difference between genome and exome lies in the scope of the sequencing process. Here are the key differences:

• Genome Sequencing: This method provides coverage across the entire genome, including both coding (exons) and non-coding (introns) regions. Genome sequencing determines the order of nucleotides in the entire genome, looking for genetic aberrations such as single nucleotide variants, deletions, insertions, and copy number variants.
• Exome Sequencing: This is a capture-based method that targets and sequences only the coding regions of the genome, referred to as "the exome". Exome sequencing focuses on the protein-coding regions, which are collectively known as the exome and make up approximately 2% of the whole genome. Most known disease-related variants are found in the exons, so exome sequencing is considered an efficient method to identify possible disease-causing mutations.

In summary, genome sequencing covers the entire genome, including both coding and non-coding regions, while exome sequencing focuses on the protein-coding regions of the genome. Exome sequencing is a more cost-effective and accessible option when whole-genome sequencing is not needed.

Comparative Table: Genome vs Exome

Here is a table comparing the differences between genome and exome:

In summary, a genome represents the entire genetic composition of an organism, including both coding and non-coding regions, while an exome comprises only the coding regions within the genome. Whole genome sequencing (WGS) is used to sequence the entire genome, while whole exome sequencing (WES) is used to sequence the exomes. WES is a more cost-effective and faster alternative to WGS, but it may not provide the same level of comprehensive information as WGS.