X-Linked Spastic Paraplegia

What is X-linked spastic paraplegia?

X-linked spastic paraplegia falls under a larger group of hereditary spastic paraplegias. This form can occur in two different ways: pure and complex. The former means that only the lower limbs are affected, whereas the latter means that the lower and upper limbs can be affected, as well as the peripheral nervous system and structure/function of the brain.

What are the symptoms of X-linked spastic paraplegia?

Symptoms typically appear between the first and fifth year of life. The pure form of X-linked spastic paraplegia only affects the legs, making them progressively stiff. This can eventually lead to paralysis of the lower limbs.

The complex form shares the same symptoms, as well as:

Ataxia
Involuntary eye movements
Tremors
Mild intellectual disability
Atrophy of the optic nerves

What causes X-linked spastic paraplegia?

A mutated PLP1 gene is responsible for this condition, and it is inherited in an X-linked recessive pattern. It is needed for the production of two proteins: proteolipid protein 1 and DM20. They are necessary to the formation of myelin, so when they are mutated, myelin is reduced, which leads to the characteristic symptoms.

How is X-linked spastic paraplegia diagnosed?

Doctors use three things to diagnose this condition. First they look for the characteristic symptoms. They then perform a neurologic exam, and lastly exclude other conditions. Genetic testing can be used as well.