RecruitingNCT01694940
Mitochondrial
Mitochondrial Complex I Deficiency
Also known as NADH dehydrogenase deficiency, complex I deficiency, mitochondrial respiratory chain complex I
Mitochondrial complex I deficiency is the most common defect of the mitochondrial respiratory chain and encompasses a heterogeneous group of disorders caused by mutations in any of the 44 subunit genes or numerous assembly factor genes of N
ORPHA:2609 ↗Gene MT-ND1-6Gene NDUFS1-8 (multiple)Prevalence Most common mitochondrial respiratory chain disorder; approximately 1 in 50,000–100,000Onset Neonatal to childhood; rarely adult
2
studies recruiting now
as of 7 Sept 2026
3
studies registered in total
as of 7 Sept 2026
3
countries with a recruiting site
as of 7 Sept 2026
4 Oct 2023
most recent study posted
among recruiting studies
Recruiting trials
RecruitingNCT06065852
National Registry of Rare Kidney Diseases
Showing the 2 most recently updated recruiting studies, as recorded 7 Sept 2026. Live status on each study page.
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About Mitochondrial Complex I Deficiency
Mitochondrial complex I deficiency is the most common defect of the mitochondrial respiratory chain and encompasses a heterogeneous group of disorders caused by mutations in any of the 44 subunit genes or numerous assembly factor genes of NADH:ubiquinone oxidoreductase. Clinical presentations range from neonatal lactic acidosis and fatal multiorgan failure to Leigh syndrome, MELAS, or isolated exercise intolerance in older individuals. Biochemical confirmation requires enzyme activity assay in muscle or fibroblasts, as blood-based assays are unreliable.
Common clinical features
Lactic acidosisHypotonia and muscle weaknessLeigh syndrome features (in early-onset cases)Encephalopathy and developmental regressionCardiomyopathyLiver dysfunctionExercise intolerance in milder phenotypes
From Orphanet’s phenotype annotations (CC BY 4.0). Not a complete list.
Before you apply
Things trial teams commonly ask about for Mitochondrial Complex I Deficiency. Not eligibility rules; those are set by each study.
- Biochemical diagnosis requires demonstration of complex I enzyme deficiency in muscle biopsy or cultured fibroblasts; blood enzyme assays are insufficient for most trial eligibility criteria.
- Genetic confirmation via comprehensive mitochondrial gene panel or whole exome sequencing with functional validation is increasingly mandated; include both mtDNA and nuclear DNA testing.
- Given the broad clinical spectrum, trials are often phenotype-specific (e.g., Leigh syndrome, cardiomyopathy); identify the predominant presenting phenotype to find the most relevant study.
Related conditions
Information, not medical advice. Trial listings are shown as recorded on ClinicalTrials.gov; whether any study is right for you is a decision for you and your clinicians, and eligibility is decided by each research team. Disease information from Orphanet (CC BY 4.0).