Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) mitochondrial neurogastrointestinal encephalopathy disease ?
    ### Response:
    Mitochondrial neurogastrointestinal encephalopathy (MNGIE) disease is a condition that affects several parts of the body, particularly the digestive system and nervous system. The major features of MNGIE disease can appear anytime from infancy to adulthood, but signs and symptoms most often begin by age 20.
    