[MIM 603 041, 612 075, 613 662]

(thymidine phosphorylase deficiency, neuro-gastro-intestinal mitochondrial encephalopathy, MEPOP syndrome,  POLIP syndrome)

Acronym for MyoNeuroGastroIntestinal disorder and Encephalopathy

Very rare. Mitochondrial cytopathy due to mitochondrial DNA depletion following:

-        a mutation of the TYMP or ECGFR1 gene (thymidine phosphorylase)(22q13.33) [MIM 603 041]. This mutation of a cytosolic enzyme leads to an imbalance in the intracellular pool of nucleotides and instability of mitochondrial DNA.

-        a mutation of the RRM2B gene (8q22.3) [MIM 612 075]

-        a mutation of the POLG gene (15q26.1) [MIM 613 662] coding for the catalytic subunit of the gamma polymerase of the DNA, necessary for mitochondrial DNA replication.

Clinical picture, starting most often from the age of 10 years:

-        gastrointestinal motility disorders: chronic abdominal pain, early satiety, gastroesophageal reflux with severe esophagitis, gastroparesis, diverticula of duodenum (risk of perforation), vomiting, diarrhea, chronic intestinal pseudo-obstruction... leading to a cachexia

-        progressive external ophthalmoplegia, ptosis

-        peripheral sensorimotor neuropathy

-        progressive often paucisymptomatic leukodystrophy

Occasionally: sensorineural hearing loss, delayed growth, muscle weakness, retinopathy; rarely: cardiomyopathy.

Anesthetic implications:

anesthetic management of a mitochondrial cytopathy and of chronic intestinal pseudo-obstruction (see these topics). Antipate a delay in gastric emptying; cachexia. A few cases have been improved (pain and transit) by neurolysis with a celiac block. Neuropathy can make neurostimulation less reliable  (nerve block or monitoring of the curarization) .

References : 

-        Celebi N, Sahin A, Canbau O, Uzücügil F, Aypar U. 
Abdominal pain related to mitochondrial neurogastrointestinal encephalomyopathy syndrome may benefit from splanchnic nerve blockade. 
Pediatr Anesth 2006 ; 16 : 1073-6.

-         Teitelbaum JE, Berde CB, Nurko S, Buonomo C, Perez-Atayde AR, Fox VL.
Diagnosis and management of MNGIE syndrome in children : case report and review of the literature. 
J Pediatr Gastroenterol Nutr 2002; 25: 377-83.

-         Baysal Z, Cengiz M, Togrul T, Cakir M. 
Anesthetic management in MNGIE syndrome. 
Internet J Anesthesiology 2006; 12: 1

-         Benureau A, Meyer P, Maillet O, Leboucq N, Legras S et al. 
L’encéphalopathie neuro-gastro-intestinale mitochondriale : un tableau d’anorexie mentale atypique. 
Arch Pédiatr 2014 ; 21 : 1370-4. 

-        Valent A, Delorme L, Roland , Lambe C, Sarnacki S, Cattan P, Plaud B.
Peri-operative management of an adult with POLG-related mitochondrial disease.
Anaesthesia Reports 2022; 10 : e12159

Updated: September 2022