All cells in our body contain DNA. Some people call DNA our “genes” or “genetic makeup.” Our DNA is passed on to us from our biological parents. As we grow and age, our body’s DNA can change in some of our cells. DNA changes that happen as we grow and age are called somatic changes. Somatic changes are not passed down, or inherited, from parents. Some cells change more than others, even within the same tissue. For example, the DNA in some of our skin cells might change even though other cells stay the same. Some DNA changes could happen because of things in our environment, like how skin cells sometimes change because of sun exposure. Some DNA changes can also happen randomly.

Somatic mosaicism describes a person’s pattern of DNA changes over time within some of the cells in their body. Somatic mosaicism is like having different genetic codes in different parts of your body. It’s like a patchwork quilt where each square has its own design. Somatic Mosaicism can lead to different traits or even health conditions in different parts of your body.