Distorted beings changed from one genetic heritage into something far off base. Victims of the F.E.V. virus and other malicious methods fall into this category, as well those who have suffered genome damage due to the highly mutagenic radioactive fallout from use of nuclear weapons during the Great War.

The vast majority of mutants do their best to survive on whatever the wasteland can provide, living hard and short lives. Not all are welcome around human settlements, and many factions will actively persecute them as the Brotherhood of Steel, the Institute and the Enclave do. Others will merely deter the most dangerous of them with structures designed to defend, such as the battlements of Fort 73.

Shortly after meeting Louise Powell, Gwendy Corner learns that not all mutants appear visibly distorted: Powell has had her growth painfully stunted by a bad thread of genetics in her family. Telling her story we also learn that other members of her family suffered from a variety of mutations like external teeth, extra semi-functional digits as well as the ubiquitous cancers, with Louise being the sole survivor of her line.