Is PROC p.Asp222= (c.666C>T) pathogenic?

PROC p.Asp222= (c.666C>T) is classified Likely benign in PROC (ClinVar, Single submitter, 1 submitter; last evaluated 2023-01-13). Very rare (popmax 0.000932%, nfe); Associated with thrombophilia due to protein C deficiency, autosomal dominant.

What condition is associated with PROC p.Asp222= (c.666C>T)?

PROC p.Asp222= (c.666C>T) is associated with thrombophilia due to protein C deficiency, autosomal dominant (ClinVar).

How common is PROC p.Asp222= (c.666C>T) in the general population?

PROC p.Asp222= (c.666C>T) is very rare (popmax 0.000932%, nfe) (gnomAD).

PROC p.Asp222=

Q: How is Severe hereditary thrombophilia due to congenital protein C deficiency inherited?

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

c.666C>T · rs771116175 · VCV2991922

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

very rare (popmax 0.000932%, nfe)

Conditions

thrombophilia due to protein C deficiency, autosomal dominant

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP -1.6
Overall
CADD	4.215	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.000932% European (non-Finnish) · 11/1,180,034 alleles

Filtering AF 0.0005% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.000366%

Overall 0.000682% 11/1,613,894 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: PROC
Protein: p.Asp222=
Coding: c.666C>T
MANE Select: NM_000312
dbSNP: rs771116175
Type: single nucleotide variant
Location: chr2:127426215 (GRCh38)
Gene constraint: LOEUF 0.894 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 82.35 · 12 PDB
Residue 222: the peptidase s1 domain

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

Disease context

thrombophilia due to protein C deficiency, autosomal dominant — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Severe hereditary thrombophilia due to congenital protein C deficiency (Orphanet):

Inheritance: Autosomal dominant, Autosomal recessive
Onset: Neonatal
Prevalence: 1-9 / 1 000 000 (Worldwide)

Similar variants

PROC p.Asp222Glu Uncertain significance ★ ⚠ same residue
PROC p.Ala309Thr Pathogenic/Likely pathogenic ★★ ⚠ same condition
PROC p.Arg199Ter Pathogenic ★★ same condition
PROC p.Arg211Gln Pathogenic/Likely pathogenic ★★ ⚠ same condition
PROC p.Arg211Trp Pathogenic/Likely pathogenic ★★ ⚠ same condition
PROC p.Arg220Gln Pathogenic/Likely pathogenic ★★ ⚠ same condition
PROC p.Arg220Trp Pathogenic/Likely pathogenic ★★ ⚠ same condition
PROC p.Arg271Trp Pathogenic/Likely pathogenic ★★ 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/proc-p-asp222 (accessed [today's date]).

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