IEMbase 0157: TYMP-related MNGIE
Scope
| Field | Value |
|---|---|
| IEMbase ID | 157 |
| Nosology | 9.1.08.01 |
| Gene | TYMP |
| External IDs | OMIM:131222; OMIM:603041; ORPHA:298 |
| Generated mapping | AMBIGUOUS: Chronic_Intestinal_Pseudoobstruction.yaml#Mitochondrial; Mitochondrial_Neurogastrointestinal_Encephalomyopathy.yaml |
| Candidate DisMech targets | Mitochondrial_Neurogastrointestinal_Encephalomyopathy.yaml; Chronic_Intestinal_Pseudoobstruction.yaml |
| Review date | 2026-07-07 |
IEMbase phenotype signal
IEMbase represents this as TYMP-related thymidine phosphorylase deficiency, with alternate labels mitochondrial depletion syndrome 1, mitochondrial neurogastrointestinal encephalomyopathy syndrome, and MNGIE. Treatability is marked unknown.
The biochemical rows show markedly decreased WBC thymidine phosphorylase in adolescence and adulthood, increased plasma and urinary thymidine and 2'-deoxyuridine, and increased plasma lactate. The clinical profile includes abdominal pain, diarrhea, vomiting, gastrointestinal dysmotility, gastroparesis, malabsorption, chronic malnutrition, intestinal pseudo-obstruction, hypodense white matter/leukoencephalopathy, areflexia, myelinating neuropathy, muscle weakness, myopathy, and ragged-red fibers.
DisMech phenotype coverage
Mitochondrial_Neurogastrointestinal_Encephalomyopathy.yaml is the correct
canonical target. It explicitly models classic TYMP-related MNGIE, thymidine
phosphorylase deficiency, systemic thymidine and 2'-deoxyuridine accumulation,
mitochondrial DNA depletion/deletions, gastrointestinal dysmotility,
pseudo-obstruction, cachexia, ptosis/progressive external ophthalmoplegia,
demyelinating peripheral neuropathy, leukoencephalopathy, skeletal myopathy,
and disease-modifying approaches such as allogeneic hematopoietic stem cell
transplantation, liver transplantation, erythrocyte-encapsulated thymidine
phosphorylase, dialysis, and investigational gene therapy.
Chronic_Intestinal_Pseudoobstruction.yaml also has a mitochondrial subtype
displayed as MNGIE and anchored on TYMP, but that entry is an umbrella CIPO
entry. It is useful secondary context for the intestinal pseudo-obstruction
phenotype, not the primary disease target for TYMP-related MNGIE.
Concordance and completeness
Judgement: generated ambiguity should resolve to the standalone MNGIE entry.
DisMech has strong concordance for gene, biochemical mechanism, nucleoside accumulation, gastrointestinal dysmotility, pseudo-obstruction, leukoencephalopathy, neuropathy, myopathy, and treatment mechanisms. IEMbase adds WBC enzyme activity as an explicit row, urinary thymidine/deoxyuridine, plasma lactate, areflexia, ragged-red fibers, and anorexia-nervosa wording as possible review details.
Curation actions
- Map IEMbase 157 to
Mitochondrial_Neurogastrointestinal_Encephalomyopathy.yaml. - Treat the CIPO mitochondrial subtype as secondary phenotype/subtype context, not as the canonical mapping.
- Consider future refinement for urinary thymidine/deoxyuridine, WBC thymidine phosphorylase, plasma lactate, and ragged-red fiber rows.