Is C8A p.Gly391Ser (c.1171G>A) pathogenic?

C8A p.Gly391Ser (c.1171G>A) is classified Uncertain significance in C8A (ClinVar, Single submitter, 1 submitter; last evaluated 2024-01-17). AlphaMissense: likely benign (0.0767); Very rare (popmax 0.0011%, sas).

How common is C8A p.Gly391Ser (c.1171G>A) in the general population?

C8A p.Gly391Ser (c.1171G>A) is very rare (popmax 0.0011%, sas) (gnomAD).

What do computational predictors say about C8A p.Gly391Ser (c.1171G>A)?

AlphaMissense predicts likely benign (score 0.0767) — an in-silico prediction, not a clinical call.

C8A p.Gly391Ser

c.1171G>A · rs1385164939 · VCV3136075

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.0767 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.0011%, sas)

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Computational evidence

Protein change
AlphaMissense	0.0767	likely benign
REVEL	0.056	moderately benign-leaning
SaProt	LLR -6.18	tolerated
⇒ AlphaMissense, REVEL and SaProt all call this tolerated.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Pangolin	Δ0.27	gain · loss 0.00 · not in the SpliceAI release · independent
Constraint at this position
Conservation	phyloP 0.58	GERP -1.9
Regional constraint	o/e 1.08	unconstrained · MANE · 63 kb · p 0.034 · regional, not allelic
Overall
CADD	3.865	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 0.0011% South Asian · 1/91,082 alleles

Overall 6.84e-05% 1/1,461,792 alleles · very rare

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: C8A
Protein: p.Gly391Ser
Coding: c.1171G>A
MANE Select: NM_000562
dbSNP: rs1385164939
Type: single nucleotide variant
Location: chr1:56906741 (GRCh38)
Gene constraint: LOEUF 1.168 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 79.58 · 11 PDB
Residue 391: a disulfide bond; the macpf domain

Full C8A gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Similar variants

C8A p.Arg424Ter Pathogenic ★★ same type
C8A p.Arg498Ter Pathogenic/Likely pathogenic ★★ same type
C8A p.Glu466Ter Pathogenic ★★ same type
C8A p.Tyr210Ter Pathogenic/Likely pathogenic ★★ same type
C8A p.Tyr384Ter Pathogenic/Likely pathogenic ★★ same type
C8A p.Arg107Cys Uncertain significance ★★ ⚠ same type
C8A p.Arg196His Uncertain significance ★★ ⚠ same type
C8A p.Arg207Gln 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/c8a-p-gly391ser (accessed [today's date]).

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