mitochondrial complex 2 deficiency, nuclear type 3
Findings
No curated finding names mitochondrial complex 2 deficiency, nuclear type 3 yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
A an autosomal recessive caused by pathogenic variants in the SDHD gene, leading to dysfunction of mitochondrial complex II. Clinical features are variable and may include Leigh syndrome, cardiomyopathy, and other neurological and muscular manifestations.
Definition from the Mondo Disease Ontology (MONDO:0030937), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal recessive inheritance
- Onset and course
- Infantile onset · Neonatal death · Fetal onset
HPO, annotations 2026-09-02
Features
26 features
What the disease is reported to present with, and how often among people who have it — never how often a feature means the disease. HPO, annotations 2026-09-02.
- Aspiration pneumoniaHPOHP:0011951
- 1 of 1 reported patient
- AtaxiaHPOHP:0001251
- 1 of 1 reported patient
- Decreased activity of mitochondrial complex IIHPOHP:0008314
- 2 of 2 reported patients
- Developmental regressionHPOHP:0002376
- 1 of 1 reported patient
- Dilated cardiomyopathyHPOHP:0001644
- 1 of 1 reported patient
- DystoniaHPOHP:0001332
- 1 of 1 reported patient
- Feeding difficultiesHPOHP:0011968
Show the remaining 14
- LacticaciduriaHPOHP:0003648
- 1 of 1 reported patient
- Left ventricular hypertrophyHPOHP:0001712
- 1 of 1 reported patient
- Left ventricular noncompactionHPOHP:0030682
- 1 of 1 reported patient
- Left ventricular systolic dysfunctionHPOHP:0025169
- 1 of 1 reported patient
- Mitral regurgitationHPOHP:0001653
- 1 of 1 reported patient
- MyoclonusHPOHP:0001336
- 1 of 1 reported patient
Genes
1 gene
Germline variants in the gene encoding each protein, as classified by GenCC submitters, each in their own words. Limited, disputed and refuted submissions are listed too.
- SDHDHGNC:10683
- Moderate · Ambry Genetics · Autosomal recessive · 2025
Where it sits
Other names
3 names
Resolves to: mitochondrial complex 2 deficiency, nuclear type 3
- Also called
- MC2DN3mitochondrial complex II deficiency, nuclear type 3SDHD-related Nuclear type mitochondrial complex II deficiency