Genetics is the study of genes and heredity. It focuses on the passing of traits from parents to offspring such as behavior, appearance and diseases. Environmental causes of diseases are factors within an environment that can cause diseases. Such as malaria from living in places that have infected mosquitoes that carry the disease. Lifestyle Choices are the choices an individual makes that overall affects their health. People who choose smoke can in the future have lung cancer and people who choose to drink alcohol all the time can develop liver disease. A disease caused by genetics is Huntington disease, which is a brain disorder that causes uncontrollable movements and trouble walking, speaking and swallowing food and water. It even causes a change in personality. The most common form happens to adults in their thirties and forties. There is a juvenile form of this disease that is not very common and causes seizures. It is causes by mutations in the HTT gene that creates a protein called huntingtin that is very important to the nerve cells or neurons in the brain. There is no cure but their are precription treatments that will slow it down based on the symptoms. Malaria is a blood disease that is life threatening. It is caused by being bit by a infected mosquito that releases a parasite into the body. Infected mosquitoes usually have to do with the environment. Malaria affects an individual by causing severe complications like fevers, chills, and death. Malaria is curable mostly using drugs containing Quinine. A disease caused by lifestyle choices is lung cancer. Lung Cancer is a disease that causes tumors in the lungs and serious respiratory problems. The most leading cause of lung cancer is smoking cigarettes. People with lung cancer feel fatigue, lose weight unexpectedly or suffer headaches. Other neurological symptoms include walking difficulties or memory problems. There is treatment but no cure. There is treatment for pain management and also depression that many patients feel during cancer.