Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Jacobsen syndrome ?
    ### Response:
    Jacobsen syndrome is a condition caused by a loss of genetic material from chromosome 11. Because this deletion occurs at the end (terminus) of the long (q) arm of chromosome 11, Jacobsen syndrome is also known as 11q terminal deletion disorder.  The signs and symptoms of Jacobsen syndrome vary considerably.
    