Spastic Paraplegia 42, Autosomal Dominant, also known as hereditary spastic paraplegia 42, is related to spasticity and spastic paraplegia 4, autosomal dominant. An important gene associated with Spastic Paraplegia 42, Autosomal Dominant is SLC33A1 (Solute Carrier Family 33 Member 1). Affiliated tissues include spinal cord and skeletal muscle, and related phenotypes are hyperreflexia and babinski sign