Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to COL4A1-related brain small-vessel disease ?
    ### Response:
    As the name suggests, mutations in the COL4A1 gene cause COL4A1-related brain small vessel disease. The COL4A1 gene provides instructions for making one component of a protein called type IV collagen. Type IV collagen molecules attach to each other to form complex protein networks.
    