Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Medullary cystic kidney disease 1 ?
    ### Response:
    Medullary cystic kidney disease (MCKD) is a chronic, progressive kidney disease characterized by the presence of small renal cysts that eventually lead to end stage renal failure. Symptoms typically appear at an average age of 28 years and may include polyuria (excessive production or passage of urine) and low urinary osmolality (decreased concentration) in the first morning urine.
    