NDUFB3
Chr 2ARNADH:ubiquinone oxidoreductase subunit B3
Also known as: B12, CI-B12, MC1DN25
This protein is an accessory subunit of mitochondrial Complex I (NADH dehydrogenase), which transfers electrons from NADH to the respiratory chain as the first enzyme in mitochondrial electron transport. Mutations cause mitochondrial complex I deficiency with autosomal recessive inheritance. The gene shows low constraint to loss-of-function variation (pLI ~0, LOEUF 1.94), consistent with the recessive inheritance pattern where heterozygous carriers are typically unaffected.
Definitive — sufficient evidence for diagnostic panels
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Highly tolerant — LoF variants common in population
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
88 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 | 2 | 0 | 31 | 0 | 33 |
Likely Pathogenic | 2 | 1 | 2 | 0 | 5 |
VUS | 0 | 23 | 5 | 0 | 28 |
Likely Benign | 0 | 0 | 4 | 3 | 7 |
Benign | 0 | 0 | 8 | 0 | 8 |
Conflicting | — | 2 | |||
| Total | 4 | 24 | 50 | 3 | 83 |
LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly
View in ClinVar →Protein Context — Lollipop Plot
NDUFB3 · protein map & ClinVar variants
Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.
3D Protein StructureAlphaFold
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