Is EP300 p.Ala27Val (c.80C>T) pathogenic?

EP300 p.Ala27Val (c.80C>T) is classified Benign in EP300 (ClinVar, Single submitter, 1 submitter; last evaluated 2024-07-11). AlphaMissense: likely benign (0.1723); Very rare (popmax 0.00333%, amr); Associated with Rubinstein-Taybi syndrome due to EP300 haploinsufficiency.

What condition is associated with EP300 p.Ala27Val (c.80C>T)?

EP300 p.Ala27Val (c.80C>T) is associated with Rubinstein-Taybi syndrome due to EP300 haploinsufficiency (ClinVar).

How common is EP300 p.Ala27Val (c.80C>T) in the general population?

EP300 p.Ala27Val (c.80C>T) is very rare (popmax 0.00333%, amr) (gnomAD).

What do computational predictors say about EP300 p.Ala27Val (c.80C>T)?

AlphaMissense predicts likely benign (score 0.1723) — an in-silico prediction, not a clinical call.

EP300 p.Ala27Val

c.80C>T · VCV3630372

Benign Single submitter

Classification

Benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.1723 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.00333%, amr)

Missense predictors

0/2 damaging

AlphaMissense, SaProt · REVEL no call

Conditions

Rubinstein-Taybi syndrome due to EP300 haploinsufficiency

Computational evidence

Protein change
AlphaMissense	0.1723	likely benign
REVEL	0.326	indeterminate
SaProt	LLR -7.06	tolerated
⇒ AlphaMissense and SaProt both call this tolerated; REVEL makes no call.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 7.6	GERP 1.8, phastCons 1
Regional constraint	o/e 0.96	unconstrained · MANE · 35 kb · p 0.42 · regional, not allelic
Overall
CADD	26.8	PHRED · no single calibrated threshold — expert panels disagree

AlphaMissense carries the ACMG weight for missense; REVEL and SaProt are independent agreement signals.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00333% Admixed American · 2/60,028 alleles

Filtering AF 0.000553% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.000207%

Overall 0.000137% 2/1,461,788 alleles · very rare

Rarity supports pathogenicity (ACMG PM2); frequency above a disease-specific BA1/BS1 threshold argues against it. A variant frequent in one ancestry group can be near-absent in others, so a single global figure can mislead.

Variant & gene context

Gene: EP300
Protein: p.Ala27Val
Coding: c.80C>T
MANE Select: NM_001429
Type: single nucleotide variant
Location: chr22:41093084 (GRCh38)
Gene constraint: LOEUF 0.164 · pLI 1.00 · ClinGen HI 3/3 (gnomAD)
Structure: AlphaFold pLDDT 54.88 · 60 PDB
Residue 27: the 'interaction with alx1' region; the 'disordered' region; the 'interaction with rora' region

Full EP300 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

Rubinstein-Taybi syndrome due to EP300 haploinsufficiency — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Similar variants

EP300 c.1282+1G>A Pathogenic/Likely pathogenic ★★ same condition
EP300 c.3671+1G>A Pathogenic/Likely pathogenic ★★ same condition
EP300 c.3729-2A>G Pathogenic/Likely pathogenic ★★ same condition
EP300 c.3857A>G Pathogenic/Likely pathogenic ★★ ⚠ same condition
EP300 p.Arg1055Ter Pathogenic ★★ same condition
EP300 p.Arg1312Ter Pathogenic ★★ same condition
EP300 p.Arg1356Ter Pathogenic ★★ same condition
EP300 p.Arg1462Ter Pathogenic ★★ same condition

Built on 18 open, versioned datasets — ClinVar, gnomAD, AlphaMissense, REVEL, ClinGen & more — plus Sugi Variant's own cross-source analysis. Source data 2026-01–2026-10, ClinVar 2026-10. Full sources & versions →

Cite Sugi Variant

Gür T. Sugi Variant: A Deterministic Per-Variant Germline Reference from a Knowledge Graph for Humans and AI Agents. 2026. doi:10.5281/zenodo.21509445. This variant: https://sugi.bio/variant/ep300-p-ala27val (accessed [today's date]).

Preprint & method: sugi.bio/variant/method Machine-readable: this page as Markdown