Is C8B p.Ser30Pro (c.88T>C) pathogenic?

C8B p.Ser30Pro (c.88T>C) is classified Uncertain significance in C8B (ClinVar, Single submitter, 1 submitter; last evaluated 2025-10-01). AlphaMissense: likely benign (0.0849); Ultra-rare (popmax 0.0658%, mid).

How common is C8B p.Ser30Pro (c.88T>C) in the general population?

C8B p.Ser30Pro (c.88T>C) is ultra-rare (popmax 0.0658%, mid) (gnomAD).

What do computational predictors say about C8B p.Ser30Pro (c.88T>C)?

AlphaMissense predicts likely benign (score 0.0849) — an in-silico prediction, not a clinical call.

C8B p.Ser30Pro

c.88T>C · VCV4534310

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.0849 · ACMG-weighted

gnomAD v4.1

Rare

ultra-rare (popmax 0.0658%, mid)

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Computational evidence

Protein change
AlphaMissense	0.0849	likely benign
REVEL	0.162	moderately benign-leaning
SaProt	LLR -8.36	tolerated
⇒ AlphaMissense, REVEL and SaProt all call this tolerated.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 6.5	GERP 1.2, phastCons 1
Regional constraint	o/e 1.09	unconstrained · MANE · 37 kb · p 0.016 · regional, not allelic
Overall
CADD	21.9	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 0.0658% Middle Eastern · 4/6,078 alleles

Filtering AF 0.0224% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.0135%

Overall 0.00124% 20/1,614,002 alleles · ultra-rare

Ancestry group	Frequency	1 in
Middle Easterngrpmax	0.0658%	1,520
Admixed American	0.00833%	12,000
Remaining individualsnot grpmax-eligible	0.0048%	20,829
European (non-Finnish)	0.000678%	147,500

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: C8B
Protein: p.Ser30Pro
Coding: c.88T>C
MANE Select: NM_000066
Type: single nucleotide variant
Location: chr1:56965861 (GRCh38)
Gene constraint: LOEUF 1.18 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 81.99 · 8 PDB

Full C8B gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Similar variants

C8B p.Arg284Ter Pathogenic ★★ same type
C8B p.Arg428Ter Pathogenic ★★ same type
C8B p.Cys508Ter Pathogenic/Likely pathogenic ★★ same type
C8B p.Gln91Ter Pathogenic/Likely pathogenic ★★ same type
C8B p.Trp9Ter Pathogenic ★★ same type
C8B p.Ala21Thr Uncertain significance ★★ ⚠ same type
C8B p.Ala446Val Uncertain significance ★★ ⚠ same type
C8B p.Ala461Ser 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/c8b-p-ser30pro (accessed [today's date]).

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