Is CHEK2 p.Ala91Pro (c.271G>C) pathogenic?

CHEK2 p.Ala91Pro (c.271G>C) is classified Uncertain significance in CHEK2 (ClinVar, Multiple submitters, 2 submitters; last evaluated 2026-05-13). AlphaMissense: likely benign (0.0998); Absent from gnomAD v4.1; Associated with hereditary neoplastic syndrome.

What condition is associated with CHEK2 p.Ala91Pro (c.271G>C)?

CHEK2 p.Ala91Pro (c.271G>C) is associated with hereditary neoplastic syndrome, hereditary breast carcinoma (ClinVar).

How common is CHEK2 p.Ala91Pro (c.271G>C) in the general population?

CHEK2 p.Ala91Pro (c.271G>C) is absent from gnomAD v4.1 (gnomAD).

What do computational predictors say about CHEK2 p.Ala91Pro (c.271G>C)?

AlphaMissense predicts likely benign (score 0.0998) — an in-silico prediction, not a clinical call.

CHEK2 p.Ala91Pro

c.271G>C · rs2146145205 · VCV1488183

Uncertain significance Multiple submitters

Classification

Uncertain significance

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 2 submitters

AlphaMissense

likely benign

0.0998 · ACMG-weighted

gnomAD v4.1

Absent

absent from gnomAD v4.1

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

hereditary neoplastic syndrome

Computational evidence

Protein change
AlphaMissense	0.0998	likely benign
REVEL	0.246	benign-leaning
SaProt	LLR -4.82	tolerated
⇒ AlphaMissense, REVEL and SaProt all call this tolerated.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 3.6	GERP 1.5, phastCons 1
Regional constraint	o/e 1.02	unconstrained · MANE · 47 kb · p 0.57 · regional, not allelic
Overall
CADD	18.78	PHRED · no single calibrated threshold — expert panels disagree

ClinVar classifies this uncertain; the computational predictors unanimously lean tolerated — 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

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: CHEK2
Protein: p.Ala91Pro
Coding: c.271G>C
MANE Select: NM_007194
dbSNP: rs2146145205
Type: single nucleotide variant
Location: chr22:28734451 (GRCh38)
Gene constraint: LOEUF 1.399 · pLI <0.01 · ClinGen HI 3/3 (gnomAD)
Structure: AlphaFold pLDDT 77.64 · 38 PDB
Residue 91: an α-helix

Full CHEK2 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

hereditary neoplastic syndrome — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: hereditary breast carcinoma

Similar variants

CHEK2 p.Ala91Asp Uncertain significance ★★ ⚠ same residue
CHEK2 p.Ala91Val Uncertain significance ★★ ⚠ same residue
CHEK2 p.Ala91Gly Uncertain significance ★ ⚠ same residue
CHEK2 p.Ala91= Benign ★ same residue
CHEK2 p.Ala91fs Pathogenic ★ same residue
CHEK2 p.Ala91Asn Uncertain significance ★ same residue
CHEK2 c.1008+1G>A Likely pathogenic ★★ same condition
CHEK2 c.1008+1G>T 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/chek2-p-ala91pro (accessed [today's date]).

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