Mitochondrial Neurogastrointestinal Encephalopathy Syndrome

Mitochondrial neurogastrointestinal encephalopathy (MNGIE) syndrome is a condition that mainly affects the digestive system and nervous system. Signs and symptoms most often begin by age 20 and worsen with time. Almost all people with MNGIE have gastrointestinal dysmotility, in which the muscles and nerves of the digestive system do not move food through the digestive tract efficiently and result in early satiety, nausea, dysphagia, gastroesophageal reflux, vomiting after eating (postprandial emesis), episodic abdominal pain and/or distention, and diarrhea . Affected people may also have cachexia, dropped eyelids or weakness of other muscles of the eyes, peripheral neuropathy (manifesting as tingling, numbness, and pain (paresthesias) symmetric weakness, that mainly affect the lower extremities) and hearing loss. Leukoencephalopathy, which is the deterioration of a type of brain tissue known as white matter, is a hallmark of MNGIE; however it does not usually cause symptoms in people with this disorder. MNGIE is caused by variations (mutations) in the TYMP gene, important for allowing adequate levels of thymidine in the mitochondria.  Inheritance is autosomal recessive.

Diagnosis is confirmed by detecting the TYMP gene variations or the increased levels of thymidine and deoxyuridine in blood. Treatment depends on the problems that present, and may include management of the  swallowing difficulties and airway protection; specific medication for neuropathic symptoms and for  nausea and vomiting. Other treatment may include nutritional support,  antibiotics for intestinal bacterial overgrowth, special education and and physical therapy. It is recommended to avoid medication that interfere with mitochondrial function, such as valproate, phenytoin, chloramphenicol, linezolid, aminoglycosides, and tetracycline.