Mitochondrial Dna Depletion Syndrome 4b, also known as mitochondrial neurogastrointestinal encephalopathy syndrome, is related to mitochondrial dna depletion syndrome 8a and mitochondrial neurogastrointestinal encephalomyopathy, and has symptoms including abdominal pain, vomiting and intermittent diarrhea. An important gene associated with Mitochondrial Dna Depletion Syndrome 4b is POLG (DNA Polymerase Gamma, Catalytic Subunit), and among its related pathways/superpathways are Metabolism of nucleotides and Pyrimidine metabolism. Affiliated tissues include brain and eye, and related phenotypes are seizure and hearing impairment