Is THBD p.Arg278Cys (c.832C>T) pathogenic?

THBD p.Arg278Cys (c.832C>T) is classified Uncertain significance in THBD (ClinVar, Single submitter, 1 submitter; last evaluated 2024-05-07). AlphaMissense: likely pathogenic (0.8106); Very rare (popmax 0.00134%, afr); Associated with thrombomodulin-related bleeding disorder.

What condition is associated with THBD p.Arg278Cys (c.832C>T)?

THBD p.Arg278Cys (c.832C>T) is associated with thrombomodulin-related bleeding disorder, atypical hemolytic-uremic syndrome with thrombomodulin anomaly (ClinVar).

How common is THBD p.Arg278Cys (c.832C>T) in the general population?

THBD p.Arg278Cys (c.832C>T) is very rare (popmax 0.00134%, afr) (gnomAD).

How is Thrombomodulin-related bleeding disorder inherited?

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

What do computational predictors say about THBD p.Arg278Cys (c.832C>T)?

AlphaMissense predicts likely pathogenic (score 0.8106) — an in-silico prediction, not a clinical call.

THBD p.Arg278Cys

c.832C>T · VCV3587128

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely pathogenic

0.8106 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.00134%, afr)

Missense predictors

3/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

thrombomodulin-related bleeding disorder

Computational evidence

Protein change
AlphaMissense	0.8106	likely pathogenic
REVEL	0.696	pathogenic-leaning
SaProt	LLR -11.99	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 12	GERP 1.4, phastCons 1
Regional constraint	o/e 1.04	unconstrained · MANE · 1,724 bp · p 0.25 · regional, not allelic
Overall
CADD	28.3	PHRED · no single calibrated threshold — expert panels disagree

ClinVar classifies this uncertain; the computational predictors unanimously lean damaging — 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 0.00134% African / African-American · 1/74,826 alleles

Overall 0.000126% 2/1,587,896 alleles · very rare exomes 2/1,435,544 · genomes 0/152,352 · joint denominator

Ancestry group	Frequency	1 in
African / African-Americangrpmax	0.00134%	74,826
European (non-Finnish)	8.52e-05%	1,174,102

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: THBD
Protein: p.Arg278Cys
Coding: c.832C>T
MANE Select: NM_000361
Type: single nucleotide variant
Location: chr20:23048673 (GRCh38)
Gene constraint: LOEUF 1.938 · pLI 0.05 (gnomAD)
Structure: AlphaFold pLDDT 79.35 · 13 PDB
Residue 278: the egf-like 1 domain

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

Disease context

thrombomodulin-related bleeding disorder — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: atypical hemolytic-uremic syndrome with thrombomodulin anomaly

For Thrombomodulin-related bleeding disorder (Orphanet):

Inheritance: Autosomal dominant
Onset: All ages

Similar variants

THBD p.Arg278Leu Uncertain significance ★ ⚠ same residue
THBD p.Cys537Ter Pathogenic/Likely pathogenic ★★ same condition
THBD p.Ala139Ser Uncertain significance ★★ ⚠ same condition
THBD p.Ala271Thr Uncertain significance ★★ ⚠ same condition
THBD p.Ala284Gly Uncertain significance ★★ ⚠ same condition
THBD p.Ala395Val Uncertain significance ★★ ⚠ same condition
THBD p.Ala471Thr Uncertain significance ★★ ⚠ same condition
THBD p.Ala545Thr 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/thbd-p-arg278cys (accessed [today's date]).

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