Mitochondrial neurogastrointestinal encephalopathy syndrome (MNGIE), also called myoneurogastrointestinal encephalopathy syndrome or POLIP syndrome, is a rare autosomalrecessivemitochondrial disease usually appearing between the second and fifth decades of life. Unlike typical mitochondrial diseases caused by mitochondrial DNA (mtDNA) mutations, MNGIE is caused by mutations in the TYMP gene, which encodes the enzymethymidine phosphorylase. A secondary form of MNGIE, called MNGIE without leukoencephalopathy, can be caused by mutations in the POLG gene.
MNGIE is a multisystem disorder. Gastrointestinal symptoms may include gastrointestinal dysmotility, possibly resulting in pseudo-obstruction in which the muscular contractions (peristalsis) of the gastrointestinal tract become inefficient, causing malabsorption . Borborygmi (stomach rumbling), early satiety, diarrhea, constipation, gastroparesis, nausea, vomiting, weight loss, diverticulitis. Neurological symptoms may include diffuse leukoencephalopathy, peripheral neuropathy, and myopathy. Ocular symptoms may include retinal degeneration, ophthalmoplegia (paralysis of eye muscles), ptosis (drooping eyelids). Those with MNGIE are often thin, experiencing continuous weight loss.
^Taanman, J. W.; Daras, M.; Albrecht, J.; Davie, C. A.; Mallam, E. A.; Muddle, J. R.; Weatherall, M.; Warner, T. T.; Schapira, A. H. V.; Ginsberg, L. (Feb 2009). "Characterization of a novel TYMP splice site mutation associated with mitochondrial neurogastrointestinal encephalomyopathy (MNGIE)". Neuromuscular Disorders19 (2): 151–154. doi:10.1016/j.nmd.2008.11.002. PMID19056268.