Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to juvenile primary lateral sclerosis ?
    ### Response:
    Mutations in the ALS2 gene cause most cases of juvenile primary lateral sclerosis. This gene provides instructions for making a protein called alsin. Alsin is abundant in motor neurons, but its function is not fully understood. Mutations in the ALS2 gene alter the instructions for producing alsin.
    