What are driver mutations? What are passenger mutations?

In a previous Health Tree University lesson, we explored germline mutations, DNA changes inherited from egg and sperm cells, and somatic mutations, which occur after conception and aren't passed down. We also learned how mutations can play a role in genetic conditions, including cancer. Now let's take our understanding even further. In this lesson, we'll dive into another way to classify mutations, driver mutations, and passenger mutations, get ready to discover how these genetic changes influence health and disease. What are driver and passenger mutations? We are all generating mutations. We all have genes in which changes are occurring in the DNA, and we never know about it because they're not bad changes. The cell doesn't survive so well, but if you've got a billion muscle cells, throwing off a cell here or there that has errors is not a big problem. If we look at all the mutations, we may find that there are sequences in the DNA that may be different than normal, but they don't have a problem. They don't cause problems. We often refer to mutations as driver mutations. They may drive a trait, so they may drive a cell to proliferate. They may drive a cell to go to the bone marrow. They may drive the cell to not die. They may drive the cell to resist a therapy. Those are actionable. There are other mutations that probably have no impact, and we often refer to those as passenger mutations. They're along for the ride. They have no particular effect on the cell. We know they're there. We know we all have mutations, but compared to the drivers that are actionable, they're just passengers along for the ride. If we use it for the whole cancer, carcinogenesis as a whole, the driver mutations are the ones which actually cause cancer. Those are the ones which are driving the diseases, driving the cancers, and they could be two different subsets. One subset is related to oncogenes. That means if you gain function of that particular gene, you can cause the cells to proliferate uncontrollably. Another subset is called the tumor suppressor genes. Those are the cells which actually, if they lose the function, meaning if they are absent, that means that the cells can proliferate uncontrollably. Example of the first one is a very common mutation in the lung cancer, EGFR mutation. Another example of oncogene is the KRAS mutation that can happen in colon cancer patients. For the tumor suppressor genes, for the loss of the gene is one of the most important and common one is called TP53. Those are, like I said, very important mutations in terms of how they cause, they provide a causality, they cause cancer. They also could be targetable. Those are the mutations that could be potentially targeted for the therapy, and they're also predictive and prognostic overall. In the context of cancer, driver mutations are those that directly contribute to the development and progression of the disease. While passenger mutations are considered to be hitchhikers, occurring in cancer cells but not contributing to cancer development or progression. To learn more about how mutations in oncogenes, tumor suppressor genes, and DNA repair genes drive cancer forward, watch the Health Tree University lessons on these specific topics in this course. If you found this Health Tree University lesson helpful, give us a like and subscribe to our channel. You can also watch the other lessons in this course on our YouTube playlist or on the Health Tree University website. To watch it on the website, go to the Health Tree University site, find the Myeloma Genetics, Genomics Module, and then click on the Basics of Genetics and Tumor Biology course.