Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) hereditary angiopathy with nephropathy, aneurysms, and muscle cramps syndrome ?
    ### Response:
    Hereditary angiopathy with nephropathy, aneurysms, and muscle cramps (HANAC) syndrome is part of a group of conditions called the COL4A1-related disorders. The conditions in this group have a range of signs and symptoms that involve fragile blood vessels. HANAC syndrome is characterized by angiopathy, which is a disorder of the blood vessels.
    