Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to alpha thalassemia ?
    ### Response:
    Alpha thalassemia typically results from deletions involving the HBA1 and HBA2 genes. Both of these genes provide instructions for making a protein called alpha-globin, which is a component (subunit) of hemoglobin.  People have two copies of the HBA1 gene and two copies of the HBA2 gene in each cell.
    