Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Blue rubber bleb nevus syndrome ?
    ### Response:
    Blue rubber bleb nevus syndrome is a condition in which the blood vessels do not develop properly in an area of the skin or other body organ (particularly the intestines).  The malformed blood vessels appear as a spot or lesion called a nevus.  The underlying blood vessel malformations are present from birth even though the nevus may not be visible until later in life.
    