GTF3C1
Chr 16general transcription factor IIIC subunit 1
Also known as: TFIIIC, TFIIIC220, TFIIICalpha
Encodes a component of transcription factor TFIIIC that is required for RNA polymerase III-mediated transcription of tRNA, 5S rRNA, and other stable RNAs. Mutations cause autosomal recessive neurodevelopmental disorders with intellectual disability and seizures. This gene is highly constrained against loss-of-function mutations (pLI ~1.0), indicating that haploinsufficiency is likely incompatible with normal development.
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Highly LoF-intolerant (top ~10% of genes)
Highly missense-constrained (top ~0.1%)
The highest-scoring mechanism for this gene is loss-of-function (haploinsufficiency).
Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312. Mechanism ranking also informed by gnomAD constraint, ClinVar, and ClinGen data.
ClinVar Variant Classifications
200 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 | 0 | 2 | 0 | 2 |
Likely Pathogenic | 0 | 0 | 1 | 0 | 1 |
VUS | 0 | 175 | 2 | 0 | 177 |
Likely Benign | 0 | 18 | 0 | 2 | 20 |
Benign | 0 | 0 | 0 | 0 | 0 |
| Total | 0 | 193 | 5 | 2 | 200 |
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.
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