Is MSH2 p.Arg55Pro (c.164G>C) pathogenic?

MSH2 p.Arg55Pro (c.164G>C) is classified Uncertain significance in MSH2 (ClinVar, Multiple submitters, 2 submitters; last evaluated 2025-08-19). AlphaMissense: likely pathogenic (0.9599); Very rare (popmax 8.48e-05%, nfe); Associated with Hereditary nonpolyposis colorectal neoplasms.

How common is MSH2 p.Arg55Pro (c.164G>C) in the general population?

MSH2 p.Arg55Pro (c.164G>C) is very rare (popmax 8.48e-05%, nfe) (gnomAD).

What do computational predictors say about MSH2 p.Arg55Pro (c.164G>C)?

AlphaMissense predicts likely pathogenic (score 0.9599) — an in-silico prediction, not a clinical call.

MSH2 p.Arg55Pro

Q: What condition is associated with MSH2 p.Arg55Pro (c.164G>C)?

MSH2 p.Arg55Pro (c.164G>C) is associated with Hereditary nonpolyposis colorectal neoplasms, hereditary neoplastic syndrome (ClinVar).

c.164G>C · rs748196422 · VCV835227

Uncertain significance Multiple submitters

Classification

Uncertain significance

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 2 submitters

AlphaMissense

likely pathogenic

0.9599 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 8.48e-05%, nfe)

Missense predictors

3/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

Hereditary nonpolyposis colorectal neoplasms

Computational evidence

Protein change
AlphaMissense	0.9599	likely pathogenic
REVEL	0.812	moderately pathogenic-leaning
SaProt	LLR -15.45	damaging
⇒ AlphaMissense, REVEL and SaProt all call this damaging.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 8.4	GERP 2.5, phastCons 1
Regional constraint	o/e 1.30	unconstrained · MANE · 80 kb · p 4.9e-24 · regional, not allelic
Overall
CADD	32.0	PHRED · no single calibrated threshold — expert panels disagree

ClinVar classifies this uncertain; the computational predictors unanimously lean damaging — 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 8.48e-05% European (non-Finnish) · 1/1,178,778 alleles

Overall 6.22e-05% 1/1,608,372 alleles · very rare exomes 1/1,455,992 · genomes 0/152,380 · joint denominator

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: MSH2
Protein: p.Arg55Pro
Coding: c.164G>C
MANE Select: NM_000251
dbSNP: rs748196422
Type: single nucleotide variant
Location: chr2:47403355 (GRCh38)
Gene constraint: LOEUF 0.672 · pLI <0.01 · ClinGen HI 3/3 (gnomAD)
Structure: AlphaFold pLDDT 85.60 · 30 PDB
Residue 55: an α-helix; a UniProt-annotated variant site (decreases protein levels)

Full MSH2 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

Hereditary nonpolyposis colorectal neoplasms — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: hereditary neoplastic syndrome

Similar variants

MSH2 p.Arg55Gln Likely benign ★★★ same residue
MSH2 p.Arg55Trp Uncertain significance ★★ ⚠ same residue
MSH2 p.Arg55Gly Conflicting classifications of pathogenicity ★ ⚠ same residue
MSH2 p.Arg55Leu Uncertain significance ★ ⚠ same residue
MSH2 p.Arg55= Likely benign ★ same residue
MSH2 p.Arg55fs Likely pathogenic ★ same residue
MSH2 c.1076+1G>A Pathogenic ★★★ same condition
MSH2 c.1076+1G>T 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/msh2-p-arg55pro (accessed [today's date]).

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