There are three types of Gaucher disease, but Type 1 is the most common form. Gaucher disease is caused when the body cannot break down fatty substances. This is because people with Gaucher disease have lower levels of an enzyme called glucocerebrosidase, which is responsible for their breakdown. In people with Gaucher disease, the fatty substances gradually accumulate within cells in different parts of the body. They accumulate in organs such as the spleen, liver, and bone marrow, and lead to various symptoms that can worsen over time. The earlier that treatment can be started, the more effective. This means that an early diagnosis is important.