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7402: Natural History of MNGIE


In this study, we plan to examine a total of 20 patients with Mitochondrial NeuroGastroIntestinal Encephalomyopathy (MNGIE) at six month intervals for up to five years. We will evaluate gastrointestinal function, lean body mass, neuropathy, neuropsychological capability, quality of life, nutrition, motor function, and biochemical parameters. We hope to learn more about the MNGIE disease as well as develop useful measures of disease status for use in future clinical trials.

For Diseases:

  • Mitochondrial Neuro Gastro Intestinal Encephalomyopathy (MNGIE)


Mitochondrial Neuro Gastro Intestinal Encephalomyopathy (MNGIE) is a rare and severe genetic disease. The onset of MNGIE is generally in the late teenage years. The major symptoms include: gastrointestinal symptoms (diarrhea, abdominal cramps, inability to eat normal size meals), weight loss, ptosis (droopy eyelids), reduced ability to move eyes, numbness, tingling, and weakness in the hands and feet. MNGIE is often fatal in adulthood.

MNGIE occurs when a person inherits two DNA mutations in the TYMP gene that encodes the protein thymidine phosphorylase (TP). With low or absent TP activity, thymidine and deoxyuridine build up to toxic levels, which in turn impair mitochondrial function (the ability of cells to produce energy). Disease symptoms develop when cells are not able to produce enough energy.

About this Study

This is a prospective, non-interventional, observational study, which means that no treatment is involved in the study. The goals are to learn about the natural history of MNGIE and to test at least one potential clinically relevant outcome measure for MNGIE which can be used in clinical trials.

We will study the natural history and laboratory features of MNGIE in 10-20 patients in order to learn about the progression of the disease. In this study, we will:

  1. Perform clinical assessments of patients with MNGIE every 6 months for 5 years.

  2. Conduct blood and laboratory tests to learn about how MNGIE affects participants

Participants will attend research visits at their enrolling site once every 6 months for a period of up to five years. These outpatient visits are estimated to take less than five hours each, during which the patient will be seen by the research team for evaluation and testing.

Target Enrollment

To be eligible to participate, you must:

  • Be at least 5 years of age
  • Have been diagnosed with TP defect: homozygous or compound heterozygous mutations in the TYMP gene, or TP enzyme activity of less than 20% of normal, increased plasma Thd more than 3, micromole/L, or increased plasma dUrd more than 7.5 micromole/L

You are not eligible to participate if:

  • You are currently enrolled in an interventional (study medication or other experimental intervention) study or have been enrolled within 1 month of participation in this study.
  • You are unable to travel to New York City for research visits.
  • You are unwilling to sign the NAMDC consent.
  • You are a substance abuser.

How to participate

In order to participate, you may contact the study coordinator.


The goal of this study is to find the best way to help people with primary mitochondrial disease deal with the stress of their condition, and to help these people be better able to "bounce back," or be resilient. In order to do this, the investigators are going to test two interventions (an intervention means that it aims to change something): Promoting Resilience in Stress Management (PRISM) and clinical-focused narrative (CFN) intervention.


The investigators are going to test two interventions in this pilot study. The first is called Promoting Resilience in Stress Management (PRISM). The second is called clinical-focused narrative (CFN) intervention. These interventions involve talking with the researcher about several specific topics.

Participants will join six virtual study visits. They will be assigned to the PRISM group or the CFN group. During the first study visit, participants will learn about the study and will fill out consent forms if they want to participate. In the next four visits, participants will receive one of the study interventions (PRISM or CFN). Some interventions will be supported with a digital app for participants to track progress and review what was talked about in the intervention. The sixth virtual study visit will be a discussion group that happens a couple months after participants finish the intervention.

Participants will also be sent several surveys to complete. One set of surveys is sent just once after the participant enrolls in the study. Another set of surveys is sent after the participant enrolls and again after the participant finishes the interventions.

The study team will review participants' medical records to confirm they have primary mitochondrial disease and to review the genetic diagnosis. If participants do not have copies of their own medical records or if the study team does not already have access to them, the study team will ask participants to sign a release form to obtain a copy of the medical records and/or genetic testing report.

How to participate

In order to participate in a study, you may contact any of the participating sites.