There are a lot of risk factors for getting asthma. The exact reasons for each is not yet clearly understood. Some of the factors are believed to come from genetics. A person inherits genetic mutations from one or both of their parents that may increase the chances of developing asthma. "Epigenetics", which are changes in the way a gene acts, may also increase their chances of getting asthma. These epigenetic changes may also be inherited. They may happen when a baby is still growing inside its mother, or during childhood.