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IEMbase 0446: DARS2-related mitochondrial aspartyl-tRNA synthetase deficiency

Scope

Field Value
IEMbase ID 446
Nosology 10.2.04.01
Gene DARS2
External IDs OMIM:611105; ORPHA:137898
Generated mapping UNMAPPED; low candidate 3-Hydroxy-3-Methylglutaryl-CoA_Synthase_Deficiency.yaml
Candidate DisMech targets No exact local target
Review date 2026-07-07

IEMbase phenotype signal

IEMbase represents DARS2-related mitochondrial aspartyl-tRNA synthetase deficiency, also called leukoencephalopathy with brainstem and spinal cord involvement and lactate elevation (LBSL). It records autosomal recessive inheritance. Biochemical rows include increased plasma lactate in childhood, adolescence, or adulthood. Clinical rows include leukoencephalopathy, cerebellar ataxia, spasticity, axonal neuropathy, cognitive decline, and death. There are no treatment rows.

DisMech phenotype coverage

There is no exact local DisMech target for DARS2/LBSL. No local DARS2- or LBSL-specific disease file was identified. Local leukodystrophy files, including vanishing white matter disease, describe other genetic mechanisms and should not be used as substitutes.

The generated 3-Hydroxy-3-Methylglutaryl-CoA_Synthase_Deficiency.yaml candidate is a false positive. Local HMGCS2 deficiency is a hepatic ketogenesis disorder causing hypoketotic metabolic decompensation; it does not represent a mitochondrial aminoacyl-tRNA synthetase disorder or LBSL.

Concordance and completeness

Judgement: true DARS2/LBSL local gap; reject HMG-CoA synthase deficiency as an exact mapping.

The generated candidate shares nonspecific metabolic vocabulary only. The gene, mechanism, white-matter disease framing, neurologic phenotype, and biochemical context differ.

Curation actions

  • Keep this record unmapped until a DARS2 mitochondrial aspartyl-tRNA synthetase deficiency or LBSL target exists.
  • Do not map to 3-Hydroxy-3-Methylglutaryl-CoA_Synthase_Deficiency.yaml.
  • Do not substitute EIF2B-related vanishing white matter disease for DARS2/LBSL.
  • If curated, include DARS2, autosomal recessive inheritance, mitochondrial aspartyl-tRNA synthetase dysfunction, leukoencephalopathy with brainstem and spinal cord involvement, lactate elevation, cerebellar ataxia, spasticity, axonal neuropathy, cognitive decline, and death.