What are some examples of rare diseases?
Examples of rare diseases caused by single-gene mutations include cystic fibrosis, which affects the respiratory and digestive systems; muscular dystrophies, which affect the muscles; and Huntington disease, which affects the brain and nervous system. Single genes are also responsible for some rare, inherited types of cancer. Examples of these are the BRCA1/2 genes, which increase the risk for hereditary breast and ovarian cancers, and the FAP gene, which increases the risk for hereditary colon cancer. Rare diseases related to environmental factors include uncommon types of anemia caused by vitamin-deficient diets or certain medications. A rare cancer caused by environmental factors is mesothelioma, which affects the cells lining the chest cavity. More than 90 percent of mesothelioma cases stem from exposure to asbestos, a fibrous mineral once widely used in fireproofing and insulation materials.
