Spastic paraplegia type 7

Spastic paraplegia type 7 (also called SPG7) is one of more than 80 genetic disorders known as hereditary spastic paraplegias. These disorders primarily affect the brain and spinal cord (central nervous system),specifically nerve cells (neurons) that extend down the spinal cord. These neurons are used for muscle movement and sensation.Signs and symptoms of hereditary spastic paraplegias are characterized by progressive muscle stiffness (spasticity) in the legs and difficulty walking. 

Hereditary spastic paraplegias are divided into two types: pure and complex. The pure types generally involve only spasticity of the lower limbs and walking difficulties. The complex types involve more widespread problems with the nervous system; the structure or functioning of the brain; and the nerves connecting the brain and spinal cord to muscles and sensory cells that detect sensations such as touch, pain, heat, and sound (the peripheral nervous system). In complex forms, there can also be features outside of the nervous system. Spastic paraplegia type 7 can occur in either the pure or complex form.

Like all hereditary spastic paraplegias, spastic paraplegia type 7 involves spasticity of the leg muscles and some muscle weakness. People with this form of spastic paraplegia can also have ataxia; a pattern of movement abnormalities known as parkinsonism; exaggerated reflexes (hyperreflexia) in the arms; speech difficulties (dysarthria); difficulty swallowing (dysphagia); involuntary movements of the eyes (nystagmus); mild hearing loss; abnormal curvature of the spine (scoliosis); high-arched feet (pes cavus); numbness, tingling, or pain in the arms and legs (sensory neuropathy); disturbance in the nerves used for muscle movement (motor neuropathy); and muscle wasting (amyotrophy). The onset of symptoms varies greatly among those with spastic paraplegia type 7; however, abnormalities in muscle tone and other features usually become noticeable in adulthood.