Is EP300 p.Arg754Pro (c.2261G>C) pathogenic?

EP300 p.Arg754Pro (c.2261G>C) is classified Uncertain significance in EP300 (ClinVar, Single submitter, 1 submitter; last evaluated 2022-09-30). AlphaMissense: ambiguous (0.4338); Absent from gnomAD v4.1; Associated with Rubinstein-Taybi syndrome due to EP300 haploinsufficiency.

What condition is associated with EP300 p.Arg754Pro (c.2261G>C)?

EP300 p.Arg754Pro (c.2261G>C) is associated with Rubinstein-Taybi syndrome due to EP300 haploinsufficiency (ClinVar).

How common is EP300 p.Arg754Pro (c.2261G>C) in the general population?

EP300 p.Arg754Pro (c.2261G>C) is absent from gnomAD v4.1 (gnomAD).

What do computational predictors say about EP300 p.Arg754Pro (c.2261G>C)?

AlphaMissense predicts ambiguous (score 0.4338) — an in-silico prediction, not a clinical call.

EP300 p.Arg754Pro

c.2261G>C · rs544338126 · VCV2026841

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

ambiguous

0.4338 · ACMG-weighted

gnomAD v4.1

Absent

absent from gnomAD v4.1

Conditions

Rubinstein-Taybi syndrome due to EP300 haploinsufficiency

Computational evidence

Protein change
AlphaMissense	0.4338	ambiguous
REVEL	0.536	indeterminate
SaProt	LLR -5.83	tolerated
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 12	GERP 2.3, phastCons 1
Regional constraint	o/e 1.10	unconstrained · MANE · 11 kb · p 0.024 · regional, not allelic
Overall
CADD	26.3	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

Absent from gnomAD v4.1. Not observed in any sequenced alleles — a rarity signal (ACMG PM2-supporting), not evidence of pathogenicity on its own.

Variant & gene context

Gene: EP300
Protein: p.Arg754Pro
Coding: c.2261G>C
MANE Select: NM_001429
dbSNP: rs544338126
Type: single nucleotide variant
Location: chr22:41149057 (GRCh38)
Gene constraint: LOEUF 0.164 · pLI 1.00 · ClinGen HI 3/3 (gnomAD)
Structure: AlphaFold pLDDT 54.88 · 60 PDB
Residue 754: the 'disordered' 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 p.Arg754Leu Uncertain significance ★★ same residue
EP300 p.Arg754His Uncertain significance ★ ⚠ same residue
EP300 p.Arg754Cys Uncertain significance ★ same residue
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

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-arg754pro (accessed [today's date]).

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