MNGIE (Mitochondrial Neurogastrointestinal Encephalomyopathy) is a rare autosomal recessive disorder caused by mutations in the TYMP gene, which leads to a deficiency of thymidine phosphorylase (TP). This deficiency results in the accumulation of thymidine and deoxyuridine, which disrupts the maintenance and integrity of mitochondrial DNA. The prevalence of MNGIE is unknown, and fewer than 200 cases have been reported in the medical literature.

The project Core Outcome Set in Mitochondrial Neurogastrointestinal Encephalomyopathy (COS-MNGIE) aims to develop a set of health outcomes (Core Outcome Set, or COS), relevant for clinicians and for people with MNGIE, that should be adopted as a minimum in clinical practice and in research on the efficacy, safety and value of treatments, including current and future permanent enzyme-replacement treatments.

To develop the Core Outcome Set, we adopted a multi-phase, consensus-driven methodology designed to integrate scientific evidence with the perspectives of clinicians and people with MNGIE. The project is promoted by the Mitocon patient advocacy group for people affected by mitochondrial diseases and endorsed by the European Reference Networks for Hereditary Metabolic Disorders (MetaBERN).

An open final consensus meeting was held online on July 11th, 2025. Relevant outcomes were identified by people with MNGIE and by clinical experts, and remaining uncertainties were discussed and resolved. The meeting of the COS-MNGIE project brought together 36 participants, including clinicians, researchers, people with MNGIE and advocacy groups involved in the care and study of MNGIE.

In this document you can find the final list of outcomes resulting from the project COS-MNGIE.

Please note: This document is intended to be used only in its original format. It may be shared via direct link or distributed in its current, unaltered form. This document should not be used as the basis for original scientific publications or adapted independently. A peer-reviewed scientific publication detailing the Core Outcome Set is currently undergoing.

For more information or to report use of this document, please contact cochrane.mito@ausl.bologna.it