What is a Polygenic Risk Score?
A risk score is a number that describes how much your variants influence a given trait, condition, or disease. In other words, whether your variants increase or decrease the chance of this trait, condition, or disease.
In real life, most traits or diseases are the result of many genes acting together. A polygenic risk score (PRS) is a number that describes your combined risk from many (‘poly-’) genes (‘-genic’).
Traits influenced by many genetic variants tend to follow a bell-shaped curve. Most people are close to the average value (center), while extreme values are rare.
Take height, for example. Individuals are not simply tall or short—we can be any height from below 4 feet to over 7 feet!
Note that the environment and your lifestyle also influence most of your traits.