IEMbase 0445: TRMU-related transient infantile liver failure

Scope

Field	Value
IEMbase ID	445
Nosology	10.1.12.01
Gene	TRMU
External IDs	OMIM:613070; ORPHA:90641
Generated mapping	UNMAPPED; low candidate Guanidinoacetate_Methyltransferase_Deficiency.yaml
Candidate DisMech targets	Partial TRMU context in Reversible_Infantile_Cytochrome_c_Oxidase_Deficiency.yaml
Review date	2026-07-07

IEMbase phenotype signal

IEMbase represents TRMU-related tRNA 5-methylaminomethyl-2-thiouridylate-methyltransferase deficiency, also called transient infantile liver failure. It records autosomal recessive inheritance. Biochemical rows include decreased multiple OXPHOS enzyme activities in muscle. Clinical rows emphasize neonatal or infantile jaundice, vomiting, coagulopathy, hepatosplenomegaly, liver failure, and pancreatic failure. IEMbase records cysteine as a pharmacological treatment row.

DisMech phenotype coverage

The generated Guanidinoacetate_Methyltransferase_Deficiency.yaml candidate is a false positive. Local GAMT deficiency is a creatine-biosynthesis disorder with guanidinoacetate accumulation and neurologic disease; it is unrelated to TRMU mitochondrial tRNA modification and infantile liver failure.

Reversible_Infantile_Cytochrome_c_Oxidase_Deficiency.yaml contains relevant TRMU context: it treats TRMU as genetic heterogeneity or a nuclear contributor to a phenotypically similar reversible infantile respiratory-chain deficiency and includes the L-cysteine/TRMU functional relationship. However, that local file is centered on MT-TE reversible infantile cytochrome c oxidase deficiency, not a dedicated TRMU transient infantile liver failure entity with liver, coagulation, pancreatic, and hepatosplenomegaly rows.

Concordance and completeness

Judgement: partial false negative/context mapping. The local reversible infantile cytochrome c oxidase deficiency file captures TRMU-related mechanism and cysteine context, but a dedicated TRMU transient infantile liver failure target remains a gap if DisMech intends to model the liver-failure phenotype as its own disease entity.

Curation actions

• Do not map to Guanidinoacetate_Methyltransferase_Deficiency.yaml.
• Use Reversible_Infantile_Cytochrome_c_Oxidase_Deficiency.yaml only as TRMU-related heterogeneity and cysteine-mechanism context.
• Before importing the IEMbase liver-failure rows, decide whether to create a dedicated TRMU transient infantile liver failure target or an explicit subtype under an existing mitochondrial tRNA-modification/respiratory-chain disease file.
• If curated, include TRMU, autosomal recessive inheritance, mitochondrial tRNA thiolation or modification, decreased muscle OXPHOS enzyme activities, transient infantile liver failure, jaundice, vomiting, coagulopathy, hepatosplenomegaly, pancreatic failure, and cysteine responsiveness.