Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Primary hyperoxaluria type 2 ?
    ### Response:
    Primary hyperoxaluria type 2  is a rare condition characterized by the overproduction of a substance called oxalate (also called oxalic acid). In the kidneys, the excess oxalate combines with calcium to form calcium oxalate, a hard compound that is the main component of kidney stones.
    