False!
Almost all diseases are a consequence of interactions between genes and environment. A genetic factor can give a predisposition for some disease, but individuals can respond differently to environmental agents, and thus could develop or not the disease. For example, the genetic factors are responsible for high blood pressure. But, they are not the only factors. Environmental factors, such as chronic stress, diet, alcohol consumption, physical inactivity, will increase the chance for development of the high blood pressure.
