ON THIS PAGE: You will find out more about the factors that increase the chance of developing this type of cancer. To see other pages, use the menu on the side of your screen.
A risk factor is anything that increases a person’s chance of developing cancer. Although risk factors often influence the development of cancer, most do not directly cause cancer. Some people with several risk factors never develop cancer, while others with no known risk factors do.
Although doctors don’t know what causes the vast majority of childhood leukemia, some evidence shows that certain genetic factors play a role in ALL. Children who are born with conditions that have been linked to genetic and immune system problems, such as Down syndrome, ataxia telangiectasia , and Bloom syndrome, may have a higher risk of developing leukemia. A child with an identical twin that develops ALL before age six has an increased risk of developing leukemia. If an identical twin develops leukemia within the first few months of life, the other twin will almost always develop the same type of leukemia.
The next section in this guide is Symptoms and Signs  and it explains what body changes or medical problems this disease can cause. Or, use the menu on the side of your screen to choose another section to continue reading this guide.