The differences in the DNA from person to person are called variants. This small portion of our DNA sequence is what makes us unique. In this section, we’ll explain how DNA variants can cause different outcomes in the body — much like different ingredients in a recipe.
There is about 1% of our DNA sequence that differs from person to person in the general population which is what makes us unique from each other. The differences in the DNA between people are called variants.
DNA sequence variants are like different ingredients in a recipe.
These DNA sequence variants can cause different outcomes in the body. Just like different ingredients in a recipe can cause different outcomes for the cookie.
For example, if you add chocolate chips to an oatmeal cookie, the cookie just gets better. If you have a particular variant that leads to a positive outcome, like being a very fast runner, that could be a good thing!*
Sometimes the ingredients you use to make cookies don’t really change the outcome. This is like using milk chocolate chips instead of dark chocolate chips, or replacing butter with margarine, in a cookie recipe. So some genetic variants may only change the color of your hair or the size of your feet; changes that are neither good nor bad, and do not really affect the way the body works at all.
Imagine what would happen though, if you replaced sugar with salt in a cookie recipe by accident… having all that salt and no sugar would make for a very different cookie. Similarly, in our bodies, some DNA sequence variants might lead to a health problem or something doctors might call a “disease,” “condition” “disorder” or “syndrome.”
A genetic condition can be caused in whole or in part by a change in the DNA sequence that differs from the normal sequence. We call variants that cause disease “mutations.”