TACO1

Chr 17AR

translational activator of cytochrome c oxidase I

Also known as: CCDC44, MC4DN8

NCBI Gene: 51204ENSG00000136463UniProt: Q9BSH4

This gene encodes a mitochondrial protein that function as a translational activator of mitochondrially-encoded cytochrome c oxidase 1. Mutations in this gene are associated with Leigh syndrome.[provided by RefSeq, Mar 2010]

Primary Disease Associations & Inheritance

Mitochondrial complex IV deficiency, nuclear type 8MIM #619052
AR
0
Active trials
26
Pathogenic / LP
190
ClinVar variants
4
Pubs (1 yr)
0.9
Missense Z
1.09
LOEUF
Clinical Summary— TACO1
🧬
Gene-Disease Validity (ClinGen)
Leigh syndrome · ARModerate

Moderate evidence — consider for supplementary testing

2 total gene-disease associations curated

⚡
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.
📋
ClinVar Variants
26 Pathogenic / Likely Pathogenic· 98 VUS of 190 total submissions
📖
GeneReview available — TACO1
Authoritative clinical overview · Recommended first read
Open GeneReview ↗

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD
Tolerant — LoF & missense variants common in population
LoF Constraint?LOEUF (Loss-of-function Observed/Expected Upper bound Fraction) is the upper bound of the 90% CI for LoF OE — the preferred gnomAD v4 metric. Lower = more intolerant to LoF. LOEUF < 0.35 = highly constrained.
1.09LOEUF
pLI 0.001
Z-score 1.37
OE 0.55 (0.30–1.09)
Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint?Missense Z-score: standard deviations fewer missense variants observed vs. expected. Z > 3.09 (p < 0.001) = gene does not tolerate missense variation. OE missense < 0.6 is also considered constrained.
0.94Z-score
OE missense 0.80 (0.69–0.92)
133 obs / 167.1 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios?Shaded band = 90% confidence interval. Vertical tick = point estimate. Grey threshold line = gnomAD constraint cutoff for that variant class.
LoF OE?Ratio of observed to expected LoF variants. Upper CI bound (LOEUF) ≤ 0.35 = strong LoF constraint signal.0.55 (0.30–1.09)
0≤0.351.4
Missense OE?Ratio of observed to expected missense variants. OE ≤ 0.6 = fewer missense variants than expected by chance.0.80 (0.69–0.92)
0≤0.61.4
Synonymous OE?Control metric — synonymous variants are largely neutral and expected near OE = 1.0. Significant deviation may indicate annotation issues.1.09
0≤1.21.6
LoF obs/exp: 6 / 10.9Missense obs/exp: 133 / 167.1Syn Z: -0.57

ClinVar Variant Classifications

190 submitted variants in ClinVar

ClinVar

Classification Summary

Pathogenic12
Likely Pathogenic14
VUS98
Likely Benign50
Benign9
Conflicting7
12
Pathogenic
14
Likely Pathogenic
98
VUS
50
Likely Benign
9
Benign
7
Conflicting

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
1
0
11
0
12
Likely Pathogenic
9
1
4
0
14
VUS
1
81
13
3
98
Likely Benign
0
4
15
31
50
Benign
0
1
8
0
9
Conflicting
—7
Total11875134190

LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly

View in ClinVar →

Protein Context — Lollipop Plot

TACO1 · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

Gene2Phenotype Curations

TACO1-related Leigh syndrome due to mitochondrial complex IV deficiency

strong
ARLoss Of FunctionAbsent Gene Product
Dev. Disorders
G2P ↗

Gene2Phenotype curations · DECIPHER consortium patient cohort (public variants) · deciphergenomics.org

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

ClinicalTrials.gov

No active trials found for this gene.

Search ClinicalTrials.gov →
Clinical Literature
Landmark / reviewRecent case evidence
Full-Text Mentions
NLP-detected gene mentions in article bodies · via PubTator3
PubTator3
Top 4 full-text resultsSearch PubTator3 ↗
Key Publications
Landmark & review papers · by relevance
PubMed
Top 5 results · since 2015Search PubMed ↗
Recent Gene-Specific Literature
Gene in title · MEDLINE · newest first
Europe PMC
Top 5 resultsSearch Europe PMC ↗

External Resources

Links to major genomics databases and tools

Franklin by Genoox
AI-powered variant curation and clinical analysis
DECIPHER
Genomic variants and phenotypes in rare disease patients