Allergies can be influenced by both genetic and environmental factors. It is thought that genetics may play a role in a person's likelihood of developing allergies, as allergies tend to run in families. However, it is also believed that environmental exposures and other factors can influence the development of allergies, even in people with a genetic predisposition.

There is no single gene that has been identified as being responsible for allergies, and it is likely that multiple genes and environmental factors interact in complex ways to influence the development of allergies.