Roussy–Lévy syndrome

Roussy–Lévy syndrome, also known as Roussy–Lévy areflexic dystasia, is a rare disorder of humans that results in progressive muscle wasting. It is caused by a mutation of the genes that code for proteins necessary for the functioning of the myelin sheath affecting the conductance of nerve signals and resulting in loss of muscles' ability to move. The condition affects people from infants through adults.