Germline vs. Somatic Genetic Testing
Germline genetic testing and somatic genetic testing are two types of testing that are used to examine an individual's genetic makeup. Both types have been available since the early 1990s when techniques for identifying genetic changes were first developed, but the ability to perform them has improved significantly over the years as newer technologies and techniques have been developed. For perspective, The Human Genome Project, based on the Sanger sequencing method, took about 13 years and three billion dollars to complete the first sequenced human genome. Today, it’s possible to sequence a genome for significantly less with advances in technology. While both types of testing can provide valuable insights into an individual's genetic health, there are several key differences between the two.
What is germline genetic testing?
Germline testing examines an individual's germline DNA, which is the DNA that is passed down from a person’s birth parents. Germline testing is often used to identify inherited genetic conditions or predispositions to certain diseases, such as breast and ovarian cancer, Lynch Syndrome, or Familial Hypocholesterolemia (inherited high cholesterol). Once these inherited conditions are identified, a primary care physician can work with their patient to proactively treat or prevent disease onset.
What is somatic germline testing?
Somatic testing examines the DNA of specific tissues or cells in the body to see if there’s been an alteration in DNA that occurred after conception. This type of testing is typically used to diagnose if someone has already developed cancer or to help determine the best treatment option for a person with cancer. Somatic mutations can be caused by activities like tobacco use, ultraviolet light or radiation, viruses, chemical exposures, and aging. Somatic testing is commonly performed on tissue samples taken from the specific body area where cancer is present but can also be done through a liquid biopsy of a blood sample with circulating tumor cells.
The future of genetic testing
Our mission at Helix is to empower people to improve their lives through DNA which is why we are creating equitable access to genetic testing with the vision that it will become the standard of care for the general population. Proactive treatment through genetic testing provides the benefit of lasting health to patients and reduces financial stress to health systems and insurance providers.
Citation:
A $100 genome? New DNA sequencers could be a ‘game changer’ for biology, medicine