Is ERBB2 p.Pro128Arg (c.383C>G) pathogenic?

ERBB2 p.Pro128Arg (c.383C>G) is classified Uncertain significance in ERBB2 (ClinVar, Multiple submitters, 3 submitters; last evaluated 2025-08-12). AlphaMissense: likely benign (0.0765); Very rare (popmax 0.00533%, afr).

How common is ERBB2 p.Pro128Arg (c.383C>G) in the general population?

ERBB2 p.Pro128Arg (c.383C>G) is very rare (popmax 0.00533%, afr) (gnomAD).

What do computational predictors say about ERBB2 p.Pro128Arg (c.383C>G)?

AlphaMissense predicts likely benign (score 0.0765) — an in-silico prediction, not a clinical call.

ERBB2 p.Pro128Arg

c.383C>G · rs373824622 · VCV134088

Uncertain significance Multiple submitters

Classification

Uncertain significance

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 3 submitters

AlphaMissense

likely benign

0.0765 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.00533%, afr)

Missense predictors

0/2 damaging

AlphaMissense, SaProt · REVEL no call

Computational evidence

Protein change
AlphaMissense	0.0765	likely benign
REVEL	0.33	indeterminate
SaProt	LLR -7.17	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 0.29	GERP 2.5
Regional constraint	o/e 0.71	unconstrained · MANE · 16 kb · p 1.3e-16 · regional, not allelic
Overall
CADD	16.05	PHRED · no single calibrated threshold — expert panels disagree

ClinVar classifies this uncertain; the computational predictors unanimously lean tolerated — a triage signal, not a reclassification

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

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00533% African / African-American · 4/75,066 alleles

Filtering AF 0.00174% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00104%

Overall 0.00031% 5/1,614,206 alleles · very rare

Ancestry group	Frequency	1 in
African / African-Americangrpmax	0.00533%	18,767
South Asian	0.0011%	91,086

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: ERBB2
Protein: p.Pro128Arg
Coding: c.383C>G
MANE Select: NM_004448
dbSNP: rs373824622
Type: single nucleotide variant
Location: chr17:39708478 (GRCh38)
Gene constraint: LOEUF 0.518 · pLI 0.06 (gnomAD)
Structure: AlphaFold pLDDT 74.65 · 63 PDB
Residue 128: an α-helix

Full ERBB2 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Similar variants

ERBB2 p.Pro128Ala Uncertain significance ★ ⚠ same residue
ERBB2 p.Pro128fs Uncertain significance ★ same residue
ERBB2 p.Ala598Asp Uncertain significance ★★ ⚠ same type
ERBB2 p.Ala644Thr Uncertain significance ★★ ⚠ same type
ERBB2 p.Arg1048Cys Uncertain significance ★★ ⚠ same type
ERBB2 p.Arg188Cys Uncertain significance ★★ ⚠ same type
ERBB2 p.Arg188His Uncertain significance ★★ ⚠ same type
ERBB2 p.Arg190Gln Uncertain significance ★★ ⚠ same type

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/erbb2-p-pro128arg (accessed [today's date]).

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