What are the genetic changes related to spastic paraplegia type 4 ?
Mutations in the SPAST gene cause spastic paraplegia type 4. The SPAST gene provides instructions for producing a protein called spastin. Spastin is found throughout the body, particularly in certain nerve cells (neurons). The spastin protein plays a role in the function of microtubules, which are rigid, hollow fibers that make up the cell's structural framework (the cytoskeleton). Microtubules are also involved in transporting cell components and facilitating cell division. Spastin likely helps restrict microtubule length and disassemble microtubule structures when they are no longer needed. Mutations in spastin impair the microtubules' ability to transport cell components, especially in nerve cells; researchers believe this contributes to the major signs and symptoms of spastic paraplegia type 4.