Is CFB p.Asn331Asp (c.991A>G) pathogenic?

CFB p.Asn331Asp (c.991A>G) is classified Likely pathogenic in CFB (ClinVar, Single submitter, 1 submitter; last evaluated 2026-09-17). AlphaMissense: likely benign (0.0554); Ultra-rare (popmax 0.0601%, eas); Associated with atypical hemolytic-uremic syndrome.

What condition is associated with CFB p.Asn331Asp (c.991A>G)?

CFB p.Asn331Asp (c.991A>G) is associated with atypical hemolytic-uremic syndrome (ClinVar).

How common is CFB p.Asn331Asp (c.991A>G) in the general population?

CFB p.Asn331Asp (c.991A>G) is ultra-rare (popmax 0.0601%, eas) (gnomAD).

How is Atypical hemolytic uremic syndrome inherited?

Typically Autosomal dominant, Autosomal recessive (Orphanet). A genetic counselor can assess individual risk for a family.

What do computational predictors say about CFB p.Asn331Asp (c.991A>G)?

AlphaMissense predicts likely benign (score 0.0554) — an in-silico prediction, not a clinical call.

CFB p.Asn331Asp

c.991A>G · VCV4280400

Likely pathogenic Single submitter

Classification

Likely pathogenic

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.0554 · ACMG-weighted

gnomAD v4.1

Rare

ultra-rare (popmax 0.0601%, eas)

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

atypical hemolytic-uremic syndrome

Computational evidence

Protein change
AlphaMissense	0.0554	likely benign ⚠ discordant with ClinVar
REVEL	0.227	benign-leaning
SaProt	LLR -6.58	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 2.1	GERP -3.9, phastCons 0.98
Overall
CADD	4.967	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 0.0601% East Asian · 27/44,904 alleles

Filtering AF 0.0424% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.0364%

Overall 0.00167% 27/1,614,114 alleles · ultra-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: CFB
Protein: p.Asn331Asp
Coding: c.991A>G
MANE Select: NM_001710
Type: single nucleotide variant
Location: chr6:31948467 (GRCh38)
Gene constraint: LOEUF 0.719 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 86.54 · 28 PDB
Residue 331: the vwfa domain

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

Disease context

atypical hemolytic-uremic syndrome — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Atypical hemolytic uremic syndrome (Orphanet):

Inheritance: Autosomal dominant, Autosomal recessive, Not applicable
Onset: All ages
Prevalence: 1-9 / 1 000 000 (United States)

Similar variants

CFB p.Arg138Gln Uncertain significance ★★ ⚠ same condition
CFB p.Arg138Trp Uncertain significance ★★ ⚠ same condition
CFB p.Arg203Gln Uncertain significance ★★ ⚠ same condition
CFB p.Arg379Cys Uncertain significance ★★ ⚠ same condition
CFB p.Gln256Ter Uncertain significance ★★ same condition
CFB p.Glu601Lys Uncertain significance ★★ ⚠ same condition
CFB p.Ser284Asn Uncertain significance ★★ ⚠ same condition
CFB c.1036+111A>G Benign ★★ same condition

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/cfb-p-asn331asp (accessed [today's date]).

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