Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to GM2-gangliosidosis, AB variant ?
    ### Response:
    Mutations in the GM2A gene cause GM2-gangliosidosis, AB variant. The GM2A gene provides instructions for making a protein called the GM2 ganglioside activator. This protein is required for the normal function of an enzyme called beta-hexosaminidase A, which plays a critical role in the brain and spinal cord.
    