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. The medical problems associated with this disorder worsen with time.^[1]

Mutations in the TYMP gene (previously known as ECGF1) cause this disease. This gene provides instructions for making an enzyme called thymidine phosphorylase. Thymidine is a molecule known as a nucleoside, which (after a chemical modification) is used as a building block of DNA. Thymidine phosphorylase breaks down thymidine into smaller molecules, which helps regulate the level of nucleosides in cells.

The prevalence of the disease is unknown. About 70 people with this disorder have been reported.

• Satiety after eating only a small amount
• Dysphagia
• Nausea and vomiting
• Odynophagia
• Abdominal pain
• Diarrhea and intestinal blockage.

These gastrointestinal problems lead to extreme weight loss and reduced muscle mass (cachexia).

• Ptosis
• Opthalmoplegia

• Hearing loss
• Tingling, numbness, and weakness in their limbs
• Peripheral neuropathy, particularly in the hands and feet.

Leukoencephalopathy, which is the deterioration of a type of brain tissue known as white matter, is a hallmark of MNGIE disease. These changes in the brain can be seen with magnetic resonance imaging (MRI).