Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to methemoglobinemia, beta-globin type ?
    ### Response:
    Methemoglobinemia, beta-globin type is caused by mutations in the HBB gene. This gene provides instructions for making a protein called beta-globin. Beta-globin is one of four components (subunits) that make up hemoglobin. In adults, hemoglobin normally contains two subunits of beta-globin and two subunits of another protein called alpha-globin.
    