Skip to content

IEMbase 0574: SUCLG1-related mitochondrial DNA depletion syndrome 9

Scope

Field Value
IEMbase ID 574
Nosology 5.2.05.01
Gene SUCLG1
External IDs OMIM:245400; ORPHA:17
Generated mapping CANDIDATE; Chronic_Intestinal_Pseudoobstruction.yaml#Mitochondrial
Candidate DisMech targets No exact SUCLG1/MTDPS9 target found
Review date 2026-07-07

IEMbase phenotype signal

IEMbase represents SUCLG1-related GTP-specific succinyl-CoA synthetase ligase alpha subunit deficiency, with alternate label mitochondrial DNA depletion syndrome type 9 and abbreviation SCS-SUCLG1. The record is autosomal recessive, idiopathic subtype, of unknown treatability, and has no treatment rows.

Biochemical rows include increased urinary C4-DC methylmalonylcarnitine and succinylcarnitine, increased urinary methylmalonic acid, increased plasma lactate and lactate/pyruvate ratio, normal-to-increased ASAT/ALAT, and low-to-normal plasma glucose in infancy/neonatal periods. Clinical rows include ataxia, axial hypotonia, choreoathetosis, congenital heart defects, sensorineural deafness, dystonia, early death, failure to thrive, Leigh syndrome, liver dysfunction, peripheral neuropathy, pyramidal signs, psychomotor retardation, and seizures. Characteristic rows include necrotizing encephalopathy, feeding difficulties, hypotonia, and lactic acidosis.

DisMech phenotype coverage

The generated Chronic_Intestinal_Pseudoobstruction.yaml#Mitochondrial candidate is not an exact target. That subtype is MNGIE/TYMP-oriented mitochondrial CIPO context and does not cover SUCLG1, succinyl-CoA synthetase, mitochondrial DNA depletion syndrome type 9, methylmalonic-acid signatures, or the SUCLG1 Leigh-like encephalomyopathy phenotype.

Broad mitochondrial or Leigh entries may provide neighborhood context, but no exact SUCLG1/MTDPS9 DisMech target was found.

Concordance and completeness

Judgement: reject the CIPO mitochondrial candidate; true SUCLG1/MTDPS9 local gap.

IEMbase provides a strong seed for curation: recessive SUCLG1 disease, succinate/succinyl-CoA ligase context, methylmalonic acid and dicarboxyl- carnitine readouts, lactate and lactate/pyruvate elevation, Leigh or necrotizing encephalopathy, hypotonia, movement disorder, seizures, sensorineural deafness, liver disease, neuropathy, and early death.

Curation actions

  • Reject Chronic_Intestinal_Pseudoobstruction.yaml#Mitochondrial as an exact mapping.
  • Add SUCLG1-related MTDPS9 / SCS-SUCLG1 deficiency to the mitochondrial curation backlog.
  • Preserve IEMbase acylcarnitine, methylmalonic acid, lactate/pyruvate, Leigh, deafness, liver, neuropathy, and early-death prompts.