exomegenomesekvensointi

Exome sequencing, also known as whole exome sequencing (WES), is a method of genetic analysis that focuses on sequencing the exome, which is the protein-coding region of the genome. The human genome contains approximately 20,000 genes, and the exome, which comprises about 1% of the entire genome, encodes for the proteins that perform most of the functions in our cells. By targeting and sequencing only these crucial regions, exome sequencing offers a cost-effective approach to identifying genetic variations that may cause disease.

This technique involves isolating all the exons from a DNA sample, followed by high-throughput sequencing. The resulting sequence data is then compared to a reference genome to identify differences, known as variants. These variants can be single nucleotide changes, insertions, or deletions. Exome sequencing is particularly useful for diagnosing rare genetic disorders, especially those with a suspected Mendelian inheritance pattern, where a single gene defect is the cause. It can help pinpoint the specific gene responsible for a patient's symptoms when other diagnostic methods have failed.

While exome sequencing is powerful, it does not cover the non-coding regions of the genome, which can also play a role in gene regulation and disease. Whole genome sequencing (WGS), which analyzes the entire genome, provides a more comprehensive view but is typically more expensive and generates a larger volume of data. Despite its limitations, exome sequencing remains a valuable tool in genetic research and clinical diagnostics, offering insights into the genetic basis of many conditions.