What is genetic risk?

Risk means the possibility of harm or loss, but genetic risk refers more to your chance of inheriting a disorder or disease.

Gene changes predict some disorders

Genetic changes can affect the way DNA and proteins work. This can help scientists predict if a person will develop a specific condition. For example, a change in the sickle cell gene indicates that a person is likely to have sickle cell disease. Other gene changes may indicate a higher risk of developing Alzheimer’s disease.

How much a genetic change tells us about your chance of developing a disorder is not always clear. For some rare diseases, however, people who have certain gene changes are guaranteed to develop the disease.

Risk is harder to predict for complex disease

Complex diseases are caused by a combination of changes in genes and environmental factors such as smoking, exercise, and nutrition. For complex disease, each genetic change influences risk in different amounts. Some changes have big effects and some have small effects. The number and combination of changes in a person’s genome determine his or her overall risk of disease.

Example: Heart disease

For example, there are a number of gene changes that affect a person’s risk of getting heart disease. Nutrition, exercise, and smoking also play a big role in determining a person’s risk of heart disease.

If your genetic results indicate that you have gene changes associated with an increased risk of heart disease, it does not mean that you definitely will develop heart disease. The opposite is also true. If your genetic results show that you do not have changes associated with an increased risk of heart disease, it is still possible that you could develop heart disease.