Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to Niemann-Pick disease ?
    ### Response:
    Niemann-Pick disease types A and B is caused by mutations in the SMPD1 gene. This gene provides instructions for producing an enzyme called acid sphingomyelinase. This enzyme is found in lysosomes, which are compartments within cells that break down and recycle different types of molecules.
    