Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Iniencephaly ?
    ### Response:
    Iniencephaly is a rare birth defect caused by improper closure of the neural tube (the part of a human embryo that becomes the brain and spinal cord) during fetal development.  Iniencephaly is in the same family of neural tube defects as spina bifida, but it is more severe.
    