Is CFB p.Arg203Ter (c.607C>T) pathogenic?

CFB p.Arg203Ter (c.607C>T) is classified Uncertain significance in CFB (ClinVar, Single submitter, 1 submitter; last evaluated 2024-03-29). Very rare (popmax 0.000339%, nfe).

How common is CFB p.Arg203Ter (c.607C>T) in the general population?

CFB p.Arg203Ter (c.607C>T) is very rare (popmax 0.000339%, nfe) (gnomAD).

CFB p.Arg203Ter

c.607C>T · rs1771507919 · VCV2792409

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

Consequence

nonsense (stop-gain)

predicted LoF

gnomAD v4.1

Rare

very rare (popmax 0.000339%, nfe)

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Consequence	nonsense (stop-gain)	predicted loss-of-function; NMD-escape possible for C-terminal truncations
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 7.7	GERP 1.8, phastCons 1
Overall
CADD	38.0	PHRED · no single calibrated threshold — expert panels disagree

Predicted loss-of-function is descriptive, not an applied PVS1 code.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.000339% European (non-Finnish) · 4/1,180,012 alleles

Filtering AF 7.9e-05% ClinGen BA1/BS1 input FAF95, joint · FAF99 5.4e-05%

Overall 0.000248% 4/1,612,866 alleles · very rare exomes 3/1,460,748 · genomes 1/152,118 · joint denominator

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.Arg203Ter
Coding: c.607C>T
MANE Select: NM_001710
dbSNP: rs1771507919
Type: single nucleotide variant
Location: chr6:31947470 (GRCh38)
Gene constraint: LOEUF 0.719 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 86.54 · 28 PDB
Residue 203: a UniProt-annotated variant site (in ahus4); the sushi 3 domain; a β-strand

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

Similar variants

CFB p.Arg203Gln Uncertain significance ★★ same residue
CFB p.Arg203Leu Uncertain significance ★ ⚠ same residue
CFB p.Arg203= Likely benign ★ same residue
CFB c.2140-1G>C Uncertain significance ★★ same type
CFB c.-3G>A Uncertain significance ★★ same type
CFB p.Ala162Val Uncertain significance ★★ ⚠ same type
CFB p.Ala289Val Uncertain significance ★★ same type
CFB p.Ala567Gly 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/cfb-p-arg203ter (accessed [today's date]).

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