Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) trisomy 18 ?
    ### Response:
    Trisomy 18, also called Edwards syndrome, is a chromosomal condition associated with abnormalities in many parts of the body. Individuals with trisomy 18 often have slow growth before birth (intrauterine growth retardation) and a low birth weight. Affected individuals may have heart defects and abnormalities of other organs that develop before birth.
    