Each person’s DNA is broken up into about 3 billion nucleotides, which are the building blocks of a person’s genetic code. Exons are the pieces of a person’s DNA that make—or code—proteins. When put all together, these exons are known as the exome, which takes up just 1 percent of a person’s entire genome.
Whole exome sequencing is a targeted laboratory approach that makes it possible to identify variations in the protein-coding part of a selected gene. This can be especially valuable because most known genetic variants actually occur in exons. With whole exome sequencing, a patient’s DNA is mapped out, and specific genetic mutations and disease-causing variants are identified.
Whole exome sequencing looks at genetic variants to determine or identify the reasons for a patient’s genetic disorder or predisposition to certain genetic disorders. For example, if a patient is experiencing signs and symptoms of a genetic disorder, whole exome sequencing could identify the possible variants that could be contributing to these symptoms, as well as other genetic issues such as how a patient reacts to a certain medication.
Whole exome sequencing can give physicians a clear idea of how a patient is affected by certain genetic disorders or predispositions. From there, physicians can use information gained from whole exome sequencing to create a patient’s treatment plan going forward.