NDUFA9
Chr 12ARNADH:ubiquinone oxidoreductase subunit A9
Also known as: CC6, CI-39k, CI39k, COQ11, MC1DN26, NDUFS2L, SDR22E1
The protein is a subunit of NADH:ubiquinone oxidoreductase (complex I), the first enzyme complex in the mitochondrial electron transport chain. Mutations cause mitochondrial complex I deficiency, nuclear type 26, inherited in an autosomal recessive pattern. The pathogenic mechanism appears to involve dominant-negative effects.
Primary Disease Associations & Inheritance
Moderate evidence — consider for supplementary testing
2 total gene-disease associations curated
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Typical tolerance to LoF variation
Mild missense constraint
Predictions shown for reference only — model trained on dominant genes, not applicable to AR conditions.
The Badonyi & Marsh prediction model was trained exclusively on dominant disease genes. Predictions are not reliable for genes with autosomal recessive inheritance and are shown at reduced opacity for reference only.
Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.
ClinVar Variant Classifications
350 submitted variants in ClinVar
Classification Summary
Curated Variants Distribution
Classified variants from ClinVar · 5 ACMG categories
| Classification | LoF | Missense + Inframe | Non-coding | Synonymous | Total |
|---|---|---|---|---|---|
Pathogenic | 0 | 5 | 54 | 0 | 59 |
Likely Pathogenic | 2 | 0 | 8 | 0 | 10 |
VUS | 3 | 119 | 15 | 1 | 138 |
Likely Benign | 0 | 8 | 29 | 37 | 74 |
Benign | 0 | 3 | 37 | 1 | 41 |
Conflicting | — | 11 | |||
| Total | 5 | 135 | 143 | 39 | 333 |
LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly
View in ClinVar →Protein Context — Lollipop Plot
NDUFA9 · protein map & ClinVar variants
Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.
External Resources
Links to major genomics databases and tools
Clinical Trials
Active and recruiting trials from ClinicalTrials.gov
No active trials found for this gene.
Search ClinicalTrials.gov →External Resources
Links to major genomics databases and tools