Is EHMT1 p.His257Pro (c.770A>C) pathogenic?

EHMT1 p.His257Pro (c.770A>C) is classified Benign/Likely benign in EHMT1 (ClinVar, Multiple submitters, 5 submitters; last evaluated 2025-01-08). AlphaMissense: likely benign (0.0687); Very rare (popmax 0.00398%, nfe); Associated with Kleefstra syndrome 1.

What condition is associated with EHMT1 p.His257Pro (c.770A>C)?

EHMT1 p.His257Pro (c.770A>C) is associated with Kleefstra syndrome 1 (ClinVar).

How common is EHMT1 p.His257Pro (c.770A>C) in the general population?

EHMT1 p.His257Pro (c.770A>C) is very rare (popmax 0.00398%, nfe) (gnomAD).

What do computational predictors say about EHMT1 p.His257Pro (c.770A>C)?

AlphaMissense predicts likely benign (score 0.0687) — an in-silico prediction, not a clinical call.

EHMT1 p.His257Pro

c.770A>C · rs370539232 · VCV833765

Benign/Likely benign Multiple submitters

Classification

Benign/Likely benign

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 5 submitters

AlphaMissense

likely benign

0.0687 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.00398%, nfe)

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

Kleefstra syndrome 1

Computational evidence

Protein change
AlphaMissense	0.0687	likely benign
REVEL	0.122	moderately benign-leaning
SaProt	LLR -4.58	tolerated
⇒ AlphaMissense, REVEL and SaProt all call this tolerated.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 7.6	GERP 0.69, phastCons 1
Regional constraint	o/e 1.20	unconstrained · MANE · 144 kb · p 1.3e-07 · regional, not allelic
Overall
CADD	23.9	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 0.00398% European (non-Finnish) · 47/1,180,024 alleles

Filtering AF 0.00307% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00275%

Overall 0.00316% 51/1,614,010 alleles · very rare

Ancestry group	Frequency	1 in
European (non-Finnish)grpmax	0.00398%	25,107
African / African-American	0.00267%	37,451
East Asian	0.00223%	44,896
Remaining individualsnot grpmax-eligible	0.0016%	62,488

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: EHMT1
Protein: p.His257Pro
Coding: c.770A>C
MANE Select: NM_024757
dbSNP: rs370539232
Type: single nucleotide variant
Location: chr9:137728476 (GRCh38)
Gene constraint: LOEUF 0.159 · pLI 1.00 (gnomAD)
Structure: AlphaFold pLDDT 64.89 · 22 PDB

Full EHMT1 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

Kleefstra syndrome 1 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Similar variants

EHMT1 p.His257Arg Likely benign ★ same residue
EHMT1 c.1370-1G>C Likely pathogenic ★★ same condition
EHMT1 c.1647+2T>C Pathogenic/Likely pathogenic ★★ same condition
EHMT1 c.2193-1G>C Pathogenic ★★ same condition
EHMT1 c.2276-2A>G Pathogenic ★★ same condition
EHMT1 c.2712+1G>A Pathogenic ★★ same condition
EHMT1 c.2867+2T>C Pathogenic/Likely pathogenic ★★ same condition
EHMT1 c.3036-1G>A Pathogenic/Likely 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/ehmt1-p-his257pro (accessed [today's date]).

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