Is CFI p.Cys550Tyr (c.1649G>A) pathogenic?

CFI p.Cys550Tyr (c.1649G>A) is classified Likely pathogenic in CFI (ClinVar, Single submitter, 1 submitter; last evaluated 2026-09-17). AlphaMissense: likely pathogenic (0.9959); Absent from gnomAD v4.1; Associated with atypical hemolytic-uremic syndrome.

What condition is associated with CFI p.Cys550Tyr (c.1649G>A)?

CFI p.Cys550Tyr (c.1649G>A) is associated with atypical hemolytic-uremic syndrome (ClinVar).

How common is CFI p.Cys550Tyr (c.1649G>A) in the general population?

CFI p.Cys550Tyr (c.1649G>A) is absent from gnomAD v4.1 (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 CFI p.Cys550Tyr (c.1649G>A)?

AlphaMissense predicts likely pathogenic (score 0.9959) — an in-silico prediction, not a clinical call.

CFI p.Cys550Tyr

c.1649G>A · VCV4280444

Likely pathogenic Single submitter

Classification

Likely pathogenic

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely pathogenic

0.9959 · ACMG-weighted

gnomAD v4.1

Absent

absent from gnomAD v4.1

Missense predictors

3/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

atypical hemolytic-uremic syndrome

Computational evidence

Protein change
AlphaMissense	0.9959	likely pathogenic ✓ concordant with ClinVar · top 1% in CFI
REVEL	0.975	strongly pathogenic-leaning
SaProt	LLR -12.37	damaging
⇒ AlphaMissense, REVEL and SaProt all call this damaging.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 7.6	GERP 1.7, phastCons 1
Regional constraint	o/e 1.00	unconstrained · MANE · 61 kb · p 0.95 · regional, not allelic
Overall
CADD	28.5	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

Absent from gnomAD v4.1. Not observed in any sequenced alleles — a rarity signal (ACMG PM2-supporting), not evidence of pathogenicity on its own.

Variant & gene context

Gene: CFI
Protein: p.Cys550Tyr
Coding: c.1649G>A
MANE Select: NM_000204
Type: single nucleotide variant
Location: chr4:109740996 (GRCh38)
Gene constraint: LOEUF 1.076 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 84.50 · 2 PDB
Residue 550: a β-strand; a disulfide bond; the peptidase s1 domain

Full CFI 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

CFI p.Cys550Arg Uncertain significance ★ same residue
CFI c.1429+1G>C Pathogenic/Likely pathogenic ★★ same condition
CFI p.Ala384Thr Uncertain significance ★★ ⚠ same condition
CFI p.Arg168Gly Uncertain significance ★★ ⚠ same condition
CFI p.Arg389His Uncertain significance ★★ ⚠ same condition
CFI p.Arg448Cys Uncertain significance ★★ ⚠ same condition
CFI p.Asn70Thr Uncertain significance ★★ ⚠ same condition
CFI p.Asp208Asn Uncertain significance ★★ ⚠ 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/cfi-p-cys550tyr (accessed [today's date]).

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