Is CCDC3 p.Arg218Pro (c.653G>C) pathogenic?

CCDC3 p.Arg218Pro (c.653G>C) is classified Uncertain significance in CCDC3 (ClinVar, Single submitter, 1 submitter; last evaluated 2025-09-24). AlphaMissense: likely pathogenic (0.8991); Ultra-rare (popmax 0.0329%, sas).

How common is CCDC3 p.Arg218Pro (c.653G>C) in the general population?

CCDC3 p.Arg218Pro (c.653G>C) is ultra-rare (popmax 0.0329%, sas) (gnomAD).

What do computational predictors say about CCDC3 p.Arg218Pro (c.653G>C)?

AlphaMissense predicts likely pathogenic (score 0.8991) — an in-silico prediction, not a clinical call.

CCDC3 p.Arg218Pro

c.653G>C · VCV4649475

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely pathogenic

0.8991 · ACMG-weighted

gnomAD v4.1

Rare

ultra-rare (popmax 0.0329%, sas)

Missense predictors

2/3 damaging

AlphaMissense, REVEL, SaProt

Computational evidence

Protein change
AlphaMissense	0.8991	likely pathogenic
REVEL	0.103	moderately benign-leaning
SaProt	LLR -12.94	damaging
⇒ AlphaMissense and SaProt call this damaging; REVEL does not.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 5.9	GERP 0.42, phastCons 1
Regional constraint	o/e 1.18	unconstrained · MANE · 103 kb · p 0.00074 · regional, not allelic
Overall
CADD	27.4	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 0.0329% South Asian · 30/91,086 alleles

Filtering AF 0.0237% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.0205%

Overall 0.00235% 38/1,614,238 alleles · ultra-rare

Ancestry group	Frequency	1 in
South Asiangrpmax	0.0329%	3,036
Remaining individualsnot grpmax-eligible	0.0064%	15,627
European (non-Finnish)	0.000339%	295,009

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: CCDC3
Protein: p.Arg218Pro
Coding: c.653G>C
MANE Select: NM_031455
Type: single nucleotide variant
Location: chr10:12898576 (GRCh38)
Gene constraint: LOEUF 1.79 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 76.13

Full CCDC3 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Similar variants

CCDC3 p.Arg218Trp Uncertain significance ★ ⚠ same residue
CCDC3 p.Ala19Val Uncertain significance ★ ⚠ same type
CCDC3 p.Ala21Ser Uncertain significance ★ ⚠ same type
CCDC3 p.Ala21Thr Uncertain significance ★ ⚠ same type
CCDC3 p.Ala250Val Uncertain significance ★ ⚠ same type
CCDC3 p.Ala253Thr Uncertain significance ★ ⚠ same type
CCDC3 p.Arg20Cys Uncertain significance ★ ⚠ same type
CCDC3 p.Arg213Cys 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/ccdc3-p-arg218pro (accessed [today's date]).

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