This article waslast modified on June 7, 2020.

Differences in the genes that make up our DNA are referred to as "variations" or "variants" and they have different effects on the body. Most genetic variations in DNA do not affect a person's health. Sometimes, however, genetic variants are related to disease. This is because the information in our DNA leads to the production of numerous proteins that govern how the body works. Some genetic variants in DNA result in a protein being made differently or not at all. Sometimes the genetic variant gives the protein new activity or a new property that interferes with its normal job. The regulation of the protein may not occur correctly, and it might fail to get turned on or off at the right time or in the right tissue type. These are usually disease-causing (pathogenic) variants.