A genetic variant is a difference in a person’s DNA sequence, when compared to a standard, or “reference” sequence. All people have many such variants. Some are important for differences between individuals and groups, while others are random changes that have no significance at all. Some diseases result from a single DNA change in a particular gene. It is important to say that, overall, most changes do not cause disease. In addition, some gene variants can influence a person’s risk of developing a disease, without making it obligatory for them to ever develop any symptoms.
Last Updated: 12/02/2015