There are people out who intentionally disable themselves. For example, they'll intentionally try to amputate a limb for one reason or another. They might also want to become either deaf or blind. These cases are mostly hidden since the transabled people don't want to end up seen as crazy. In actuality, these kinds of thoughts usually aren't caused by mental illnesses, but can be seen as a neurological problem with the body's mapping.
Although it seems absurd, considering how many humans there are, anything is possible.
Most of these known transabled people also happen to be men from either Germany, Switzerland, or Canada.