Dystonia, idiopathic torsion
A form of dystonia known as early-onset torsion dystonia (also called generalized torsion dystonia) begins in childhood around the age of 12. Symptoms typically start in one part of the body, usually in an arm or leg, and eventually spread to the rest of the body within about 5 years.
Early-onset torsion dystonia is not fatal, but it can be severely debilitating