Mental Retardation, Severe, with Spasticity and Pigmentary Tapetoretinal Degeneration, also known as mental retardation, severe, with spasticity and tapetoretinal degeneration, is related to spasticity and toxic shock syndrome, and has symptoms including muscle spasticity An important gene associated with Mental Retardation, Severe, with Spasticity and Pigmentary Tapetoretinal Degeneration is MRST (Mental Retardation, Severe, With Spasticity And Tapetoretinal). Affiliated tissues include prefrontal cortex and bone marrow.