Is BRCA1 p.Val1740= (c.5220G>A) pathogenic?

BRCA1 p.Val1740= (c.5220G>A) is classified Likely benign in BRCA1 (ClinVar, Multiple submitters, 2 submitters; last evaluated 2024-10-23). Absent from gnomAD v4.1; Associated with hereditary breast ovarian cancer syndrome.

What condition is associated with BRCA1 p.Val1740= (c.5220G>A)?

BRCA1 p.Val1740= (c.5220G>A) is associated with hereditary breast ovarian cancer syndrome (ClinVar).

How common is BRCA1 p.Val1740= (c.5220G>A) in the general population?

BRCA1 p.Val1740= (c.5220G>A) is absent from gnomAD v4.1 (gnomAD).

How is Hereditary breast and/or ovarian cancer syndrome inherited?

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

BRCA1 p.Val1740=

c.5220G>A · rs2153389068 · VCV1085033

Likely benign Multiple submitters

Classification

Likely benign

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 2 submitters

gnomAD v4.1

Absent

absent from gnomAD v4.1

Conditions

hereditary breast ovarian cancer syndrome

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 0.58	GERP -3.1, phastCons 0.007
Overall
CADD	4.938	PHRED · no single calibrated threshold — expert panels disagree

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: BRCA1
Protein: p.Val1740=
Coding: c.5220G>A
MANE Select: NM_007294
dbSNP: rs2153389068
Type: single nucleotide variant
Location: chr17:43057109 (GRCh38)
Gene constraint: LOEUF 0.885 · pLI <0.01 · ClinGen HI 3/3 (gnomAD)
Structure: AlphaFold pLDDT 41.99 · 33 PDB
Residue 1740: a UniProt-annotated variant site (in fancs); a turn

Full BRCA1 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

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

For Hereditary breast and/or ovarian cancer syndrome (Orphanet):

Inheritance: Autosomal dominant
Onset: Adult, Elderly

Similar variants

BRCA1 p.Val1740Gly Uncertain significance ★ ⚠ same residue
BRCA1 p.Val1740Ala Uncertain significance ★ ⚠ same residue
BRCA1 p.Val1740Leu Uncertain significance ★ ⚠ same residue
BRCA1 c.134+3A>T Likely pathogenic ★★★ same condition
BRCA1 c.135-1G>T Pathogenic ★★★ same condition
BRCA1 c.212+1G>A Pathogenic ★★★ same condition
BRCA1 c.212+1G>T Pathogenic ★★★ same condition
BRCA1 c.212+3A>G 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/brca1-p-val1740 (accessed [today's date]).

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