What is a genetic variant?

A genetic variant is a change of nucleotides in the DNA sequence that makes up a gene. This change can have different impacts:

• Negative impact, increasing the risk of developing a disease.
• Positive impact, reducing the risk.
• Neutral impact. It is the most common.

A genetic variant implies that this region of the DNA is different from the most common sequence in the reference population. However, the same variant can be found in several individuals of that same population.

Variants are permanent and are not always inherited. When a variant occurs in an individual but not in their parents, it is called “de novo.”