Is TP53 p.Pro278His (c.833C>A) pathogenic?

TP53 p.Pro278His (c.833C>A) is classified Pathogenic in TP53 (ClinVar, Expert panel, 7 submitters; last evaluated 2026-06-04). AlphaMissense: likely pathogenic (0.9993); Absent from gnomAD v4.1; Associated with Li-Fraumeni syndrome.

What condition is associated with TP53 p.Pro278His (c.833C>A)?

TP53 p.Pro278His (c.833C>A) is associated with Li-Fraumeni syndrome, adrenocortical carcinoma, hereditary, hereditary neoplastic syndrome (ClinVar).

How common is TP53 p.Pro278His (c.833C>A) in the general population?

TP53 p.Pro278His (c.833C>A) is absent from gnomAD v4.1 (gnomAD).

How is Li-Fraumeni syndrome inherited?

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

What do computational predictors say about TP53 p.Pro278His (c.833C>A)?

AlphaMissense predicts likely pathogenic (score 0.9993) — an in-silico prediction, not a clinical call.

TP53 p.Pro278His

c.833C>A · rs876659802 · VCV376646

Pathogenic Expert panel

Classification

Pathogenic

ClinVar

Review

Expert panel ★★★☆

ClinVar · 7 submitters

AlphaMissense

likely pathogenic

0.9993 · ACMG-weighted

gnomAD v4.1

Absent

absent from gnomAD v4.1

Missense predictors

3/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

Li-Fraumeni syndrome

Computational evidence

Protein change
AlphaMissense	0.9993	likely pathogenic ✓ concordant with ClinVar · top 1% in TP53
REVEL	0.95	strongly pathogenic-leaning
SaProt	LLR -16.91	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 2.5, phastCons 1
Regional constraint	o/e 0.89	unconstrained · MANE · 6,982 bp · p 0.0085 · regional, not allelic
Overall
CADD	28.1	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: TP53
Protein: p.Pro278His
Coding: c.833C>A
MANE Select: NM_000546
dbSNP: rs876659802
Type: single nucleotide variant
Location: chr17:7673787 (GRCh38)
Gene constraint: LOEUF 0.449 · pLI 1.00 · ClinGen HI 3/3 (gnomAD)
Structure: AlphaFold pLDDT 75.83 · 321 PDB
Residue 278: a DNA-binding region; the 'interaction with axin1' region; a UniProt-annotated variant site (in sporadic cancers; somatic mutation); a UniProt-annotated variant site (in sporadic cancers; somatic mutation; requires 2 nucleotide substitutions); a UniProt-annotated variant site (in lfs; germline mutation and in sporadic cancers; somatic mutation); the 'interaction with e4f1' region; the 'interaction with dna' region; an α-helix; the 'interaction with ccar2' region; the 'interaction with hipk1' region; the 'required for interaction with znf385a' region

Full TP53 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

Li-Fraumeni syndrome — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: adrenocortical carcinoma, hereditary hereditary neoplastic syndrome

For Li-Fraumeni syndrome (Orphanet):

Inheritance: Autosomal dominant
Onset: All ages
Prevalence: 1-9 / 100 000 (United Kingdom)

Similar variants

TP53 p.Pro278Leu Pathogenic ★★ same residue
TP53 p.Pro278Ser Pathogenic/Likely pathogenic ★★ same residue
TP53 p.Pro278Thr Pathogenic/Likely pathogenic ★★ same residue
TP53 p.Pro278Ala Conflicting classifications of pathogenicity ★ ⚠ same residue
TP53 p.Pro278Arg Conflicting classifications of pathogenicity ★ ⚠ same residue
TP53 p.Pro278_Arg283dup Uncertain significance ★★ same residue
TP53 p.Pro278fs Pathogenic ★ same residue
TP53 c.375+5G>A 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/tp53-p-pro278his (accessed [today's date]).

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