Is CHRM2 p.Arg135Trp (c.403C>T) pathogenic?

CHRM2 p.Arg135Trp (c.403C>T) is classified Uncertain significance in CHRM2 (ClinVar, Single submitter, 1 submitter; last evaluated 2022-10-25). AlphaMissense: likely pathogenic (0.9945); Very rare (popmax 0.0011%, sas).

How common is CHRM2 p.Arg135Trp (c.403C>T) in the general population?

CHRM2 p.Arg135Trp (c.403C>T) is very rare (popmax 0.0011%, sas) (gnomAD).

What do computational predictors say about CHRM2 p.Arg135Trp (c.403C>T)?

AlphaMissense predicts likely pathogenic (score 0.9945) — an in-silico prediction, not a clinical call.

CHRM2 p.Arg135Trp

c.403C>T · rs748172206 · VCV1921413

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely pathogenic

0.9945 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.0011%, sas)

Missense predictors

3/3 damaging

AlphaMissense, REVEL, SaProt

Computational evidence

Protein change
AlphaMissense	0.9945	likely pathogenic
REVEL	0.763	pathogenic-leaning
SaProt	LLR -15.22	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 1.4	GERP 1, phastCons 1
Regional constraint	o/e 0.49	unconstrained · MANE · 133 bp · p 0.00013 · regional, not allelic
Overall
CADD	29.7	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 0.0011% South Asian · 1/91,076 alleles

Overall 0.000137% 2/1,461,298 alleles · very rare

Ancestry group	Frequency	1 in
Remaining individualsnot grpmax-eligible	0.0016%	62,476
South Asiangrpmax	0.0011%	91,076

Remaining individuals shows a higher raw frequency than the grpmax group above it. gnomAD excludes bottlenecked groups — Finnish, Ashkenazi Jewish, Amish and “Remaining individuals” — from grpmax, because founder effects make their frequencies unrepresentative for filtering. The table is sorted by frequency, so an excluded group can sit above the grpmax row.

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: CHRM2
Protein: p.Arg135Trp
Coding: c.403C>T
MANE Select: NM_001006630
dbSNP: rs748172206
Type: single nucleotide variant
Location: chr7:137015268 (GRCh38)
Gene constraint: LOEUF 0.555 · pLI 0.92 (gnomAD)
Structure: AlphaFold pLDDT 72.87 · 17 PDB
Residue 135: a disulfide bond

Full CHRM2 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Similar variants

CHRM2 p.Arg135Gln Uncertain significance ★ ⚠ same residue
CHRM2 p.Ala265Val Uncertain significance ★★ ⚠ same type
CHRM2 p.Arg52Cys Uncertain significance ★★ ⚠ same type
CHRM2 p.Gln358His Uncertain significance ★★ ⚠ same type
CHRM2 p.Glu305Gly Uncertain significance ★★ ⚠ same type
CHRM2 p.Gly238Ala Uncertain significance ★★ ⚠ same type
CHRM2 p.Gly254Val Uncertain significance ★★ ⚠ same type
CHRM2 p.Gly277Glu 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/chrm2-p-arg135trp (accessed [today's date]).

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