SPG3A

The SPG3A gene provides instructions for producing a protein called atlastin-1. Atlastin-1 is found throughout the body, particularly in the brain. In cells, this protein is found in structures known as the endoplasmic reticulum and the Golgi apparatus, which are involved in the movement of proteins and cell components within the cell. Atlastin-1 likely plays a role in the transportation of cell components and in the formation of the endoplasmic reticulum and Golgi apparatus, each of which is involved in the growth of axons (specialized extensions of nerve cells that transmit nerve impulses). Atlastin-1 is necessary for the formation and growth of axons; however, its precise function remains unclear.

spastic paraplegia type 3A - caused by mutations in the SPG3A gene

More than 30 mutations in the SPG3A gene have been identified in people with spastic paraplegia type 3A. Most of these mutations change one protein building block (amino acid) in the atlastin-1 protein. It remains unclear how mutations in the SPG3A gene lead to the signs and symptoms of spastic paraplegia type 3A. Researchers suggest that these mutations disrupt the structure of atlastin-1, which interferes with the protein's role in the formation and growth of axons.