Source: https://www.xcode.life/genetics/whole-exome-sequencing/
Whole Exome Sequencing
Most of the genetic variants that cause genetic disease are found in the exome. WES is a test that looks at the genetic information contained in all of our 20,000 genes (and their multiple exons) in one single test. This is different from other genetic tests that might look at only one gene (or a handful of genes) at a time.
WES is done using special technology called next-generation sequencing (NGS). A DNA sample is collected from either a blood or saliva sample given by the patient. The patient’s DNA is then compared to a reference sample (a sample that represent the ‘normal’ sequence of human DNA) in an attempt to find any differences between the patient’s DNA and the reference DNA. If there are any differences, they are reviewed by expert laboratory geneticists and expert doctors.
Diagnosing genetic disorders
WES can help identify the cause of a genetic disorder by analyzing the coding regions of a patient’s DNA and comparing them to a normal reference sequence.
Diagnosing complex syndromes
WES can help diagnose complex syndromes, such as autism, epilepsy, brain malformations, and congenital heart disease.
Diagnosing neurodevelopmental disorders
WES is often recommended to diagnose neurodevelopmental disorders, such as intellectual disability, global developmental delay, and autism spectrum disorder.
Identifying pathogenic mutations
WES can help identify pathogenic mutations that cause or contribute to common genetic diseases.
Detecting somatic mutations
WES can help detect somatic mutations, also known as mosaicism.