Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Kallmann syndrome ?
    ### Response:
    Kallmann syndrome (KS) is a condition characterized primarily by hypogonadotropic hypogonadism (HH) and absent or diminished sense of smell (anosmia or hyposmia, respectively). HH is present from birth and is due to deficiency of gonadotropin-releasing hormone (GnRH).
    