description | Protein which, if defective, causes hereditary spastic paraplegias (HSPs). HSPs are a diverse class of hereditary degenerative spinal cord disorders characterized by a slow, gradual, progressive weakness and spasticity (stiffness) of the legs. Initial symptoms may include difficulty with balance, weakness and stiffness in the legs, muscle spasms, and dragging the toes when walking. In some forms of the disorder, bladder symptoms (such as incontinence) may appear, or the weakness and stiffness may spread to other parts of the body. Rate of progression and the severity of symptoms are quite variable |