What are somatic mutations? What are germline mutations?

In a previous Health Tree University lesson, we uncovered what mutations are and why they happen. Now, it's time to take it a step further. In this lesson, we'll explore one key way mutations can be classified, unlocking a deeper understanding of genetic changes and their impact. Let's dive in. What are germline and somatic mutations? Broadly speaking, there are many ways to divide up mutations, but one of a simple scheme is whether something is somatic versus germline. Germline essentially is what you are born with. There was a mutation or alteration that occurred really at the time that your genome was created with fertilization, and hence essentially every cell in your body has that mutation. Versus somatic mutations are ones that are acquired later in life. That can occur at any point after the event of your genome's creation, including late That difference between somatic and germline is such that with germline, because it affects really every one of your cells, that is total, versus the somatic mutations are usually affecting a more local area of your tissues. Germline mutation is a mutation that affects probably every cell in the body, including your germ cells. That is, your germ cells are the egg and the sperm. What that means is a germline mutation is a change that will now be passed on to the next generation. It will be inherited. A somatic mutation occurs in the cells that are not sperm and egg, but maybe muscle tissue or stomach tissue or plasma cells. Those are mutations that may occur in what we refer to as not the germ cells, but all the other cells, which are the somatic cells, that now will stay with you. You won't pass those on. Germline mutations are passed on. Somatic mutations are all yours. Can you explain somatic and germline mutations in the context of cancer heritability? With cancers, when we're talking about the heritability and the mutations that occur with them, it's important to know what is a somatic alteration versus a germline, because it also changes what a patient's cancer risk is and how it may affect their family members. Such famous things like the BRCA gene, BRCA1, BRCA2, those are germline alterations that they can be passed on. Versus somatic alterations, which we might see local to a tumor itself, like EGFR alterations, those are not germline. Those are just really within the tumor. Those are not going to be passed along to someone's next of kin. In this lesson, we learned that germline mutations are changes to your DNA that you inherit from the egg and sperm cells during conception and can be passed down to offspring. Somatic mutations are changes to your DNA that happen after conception and are not heritable. Mutations can lead to genetic conditions that affect your health such as cancer. In our next Health Tree University lesson, we will learn another way to classify mutations. 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.