Genetics can play a part in the development of COPD, even if you have never smoked or been exposed to pollutants for an extended period of time. In particular, emphysema can be triggered by a deficiency in alpha-1 antitrypsin (AAT), which is a protein that protects the lungs from the harmful effects of white blood cells in the lungs.
However, not everyone with COPD who has never smoked has a deficiency on AAT, so it is believed that there must be other genetic triggers for COPD⁷.