GTF3C1

Chr 16

general transcription factor IIIC subunit 1

Also known as: TFIIIC, TFIIIC220, TFIIICalpha

NCBI Gene: 2975ENSG00000077235UniProt: Q12789

Enables RNA polymerase III general transcription initiation factor activity. Predicted to be involved in 5S class rRNA transcription by RNA polymerase III and transcription initiation at RNA polymerase III promoter. Located in nucleolus and nucleoplasm. Part of transcription factor TFIIIC complex. [provided by Alliance of Genome Resources, Jul 2025]

371
ClinVar variants
35
Pathogenic / LP
1.00
pLI score· haploinsufficient
0
Active trials
Clinical Summary— GTF3C1
⚡
Population Constraint (gnomAD)
Highly constrained gene — heterozygous loss-of-function variants are very rare in the population (pLI 1.00). One damaged copy is likely sufficient to cause disease.
📋
ClinVar Variants
35 Pathogenic / Likely Pathogenic· 250 VUS of 371 total submissions

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD
Dual constrained — LoF & missense intolerant
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.
0.17LOEUF
pLI 1.000
Z-score 8.52
OE 0.10 (0.07–0.17)
Highly constrained

Highly LoF-intolerant (top ~10% of genes)

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.
3.26Z-score
OE missense 0.74 (0.70–0.78)
950 obs / 1278.2 exp
Constrained

Highly missense-constrained (top ~0.1%)

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.0.10 (0.07–0.17)
0≤0.351.4
Missense OE?Ratio of observed to expected missense variants. OE ≤ 0.6 = fewer missense variants than expected by chance.0.74 (0.70–0.78)
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.1.04
0≤1.21.6
LoF obs/exp: 11 / 105.5Missense obs/exp: 950 / 1278.2Syn Z: -0.79

ClinVar Variant Classifications

371 submitted variants in ClinVar

ClinVar

Classification Summary

Pathogenic30
Likely Pathogenic5
VUS250
Likely Benign26
Benign9
30
Pathogenic
5
Likely Pathogenic
250
VUS
26
Likely Benign
9
Benign

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
0
0
30
0
30
Likely Pathogenic
0
2
3
0
5
VUS
0
236
12
2
250
Likely Benign
0
24
0
2
26
Benign
0
2
1
6
9
Total02644610320

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

View in ClinVar →

Protein Context — Lollipop Plot

GTF3C1 · protein map & ClinVar variants

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

OMIM — Genotype-Phenotype Relationships

1 OMIM entry

OMIM
Clinical Literature
Landmark / reviewRecent case evidence
Key Publications
Landmark & review papers · by relevance
PubMed
Top 10 resultsSearch PubMed ↗
Recent Gene-Specific Literature
Gene in title · MEDLINE · newest first
Europe PMC
Top 5 resultsSearch Europe PMC ↗

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

ClinicalTrials.gov

No active trials found for this gene.

Search ClinicalTrials.gov →

External Resources

Links to major genomics databases and tools