Is C2 p.Arg88Cys (c.262C>T) pathogenic?

C2 p.Arg88Cys (c.262C>T) is classified Uncertain significance in C2 (ClinVar, Single submitter, 1 submitter; last evaluated 2021-08-26). AlphaMissense: ambiguous (0.3656); Ultra-rare (popmax 0.0133%, afr).

How common is C2 p.Arg88Cys (c.262C>T) in the general population?

C2 p.Arg88Cys (c.262C>T) is ultra-rare (popmax 0.0133%, afr) (gnomAD).

What do computational predictors say about C2 p.Arg88Cys (c.262C>T)?

AlphaMissense predicts ambiguous (score 0.3656) — an in-silico prediction, not a clinical call.

C2 p.Arg88Cys

c.262C>T · rs140767210 · VCV1363686

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

ambiguous

0.3656 · ACMG-weighted

gnomAD v4.1

Rare

ultra-rare (popmax 0.0133%, afr)

Computational evidence

Protein change
AlphaMissense	0.3656	ambiguous
REVEL	0.382	indeterminate
SaProt	LLR -9.71	tolerated
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 5.9	GERP 1.9, phastCons 1
Regional constraint	o/e 0.84	unconstrained · MANE · 18 kb · p 1.1e-06 · regional, not allelic
Overall
CADD	32.0	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 0.0133% African / African-American · 10/74,936 alleles

Filtering AF 0.00723% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.0055%

Overall 0.00235% 38/1,614,090 alleles · ultra-rare

Ancestry group	Frequency	1 in
African / African-Americangrpmax	0.0133%	7,494
European (non-Finnish)	0.0022%	45,385
Admixed American	0.00167%	60,008
Remaining individualsnot grpmax-eligible	0.0016%	62,486

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: C2
Protein: p.Arg88Cys
Coding: c.262C>T
MANE Select: NM_000063
dbSNP: rs140767210
Type: single nucleotide variant
Location: chr6:31928737 (GRCh38)
Gene constraint: LOEUF 0.909 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 88.61 · 14 PDB
Residue 88: the sushi 2 domain; a β-strand

Full C2 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Similar variants

C2 p.Arg88His Uncertain significance ★★ ⚠ same residue
C2 c.1902+5G>A Uncertain significance ★★ same type
C2 c.2029+5G>A Uncertain significance ★★ same type
C2 p.Ala363Thr Uncertain significance ★★ ⚠ same type
C2 p.Ala682Glu Uncertain significance ★★ ⚠ same type
C2 p.Arg124Gln Uncertain significance ★★ ⚠ same type
C2 p.Arg129His Uncertain significance ★★ ⚠ same type
C2 p.Arg174Cys 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/c2-p-arg88cys (accessed [today's date]).

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