Is BRCA2 c.1909+1G>A pathogenic?

BRCA2 c.1909+1G>A is classified Pathogenic/Likely pathogenic in BRCA2 (ClinVar, Multiple submitters, 17 submitters; last evaluated 2025-11-24). Very rare (popmax 8.48e-05%, nfe); Associated with hereditary breast carcinoma.

What condition is associated with BRCA2 c.1909+1G>A?

BRCA2 c.1909+1G>A is associated with hereditary breast carcinoma, gastric cancer, hereditary breast ovarian cancer syndrome (ClinVar).

How common is BRCA2 c.1909+1G>A in the general population?

BRCA2 c.1909+1G>A is very rare (popmax 8.48e-05%, nfe) (gnomAD).

How is Hereditary breast cancer inherited?

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

BRCA2 c.1909+1G>A

rs587781629 · VCV141283

Pathogenic/Likely pathogenic Multiple submitters

Classification

Pathogenic/Likely pathogenic

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 17 submitters

Consequence

canonical splice-site (±1/±2)

predicted LoF

gnomAD v4.1

Rare

very rare (popmax 8.48e-05%, nfe)

Conditions

hereditary breast carcinoma

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation/SpliceAI carries the signal.
Consequence	canonical splice-site (±1/±2)	predicted loss-of-function in a haploinsufficient gene (ClinGen)
Splicing
Splice region	donor +1	canonical splice dinucleotide (donor +1) · inside the BP7-excluded zone
SpliceAI	Δ0.99	donor loss, 1 bp away · raw score · deltas
Pangolin	Δ0.73	loss · gain 0.03 · agrees with SpliceAI · independent
Constraint at this position
Conservation	phyloP 9.8	GERP 2.3, phastCons 1
Non-coding constraint	Z 0.87	1 kb window · o/e 0.94 · regional · uncalibrated
Overall
CADD	27.8	PHRED · no single calibrated threshold — expert panels disagree

Predicted loss-of-function is descriptive, not an applied PVS1 code.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 8.48e-05% European (non-Finnish) · 1/1,179,006 alleles

Overall 6.86e-05% 1/1,457,272 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: BRCA2
Coding: c.1909+1G>A
MANE Select: NM_000059
dbSNP: rs587781629
Type: single nucleotide variant
Location: chr13:32333388 (GRCh38)
Gene constraint: LOEUF 0.803 · pLI <0.01 · ClinGen HI 3/3 (gnomAD)

Full BRCA2 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

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

Also linked: gastric cancer hereditary breast ovarian cancer syndrome medulloblastoma prostate cancer Wilms tumor 1 breast-ovarian cancer, familial, susceptibility to, 1 Fanconi anemia complementation group D1 breast-ovarian cancer, familial, susceptibility to, 2 glioma susceptibility 3 pancreatic cancer, susceptibility to, 2 hereditary neoplastic syndrome

For Hereditary breast cancer (Orphanet):

Inheritance: Autosomal dominant, Multigenic/multifactorial
Onset: Adult, Elderly

Similar variants

BRCA2 c.316+1G>T Pathogenic ★★★ same condition
BRCA2 c.316+2T>C Pathogenic ★★★ same condition
BRCA2 c.316+5G>A Pathogenic ★★★ same condition
BRCA2 c.316+5G>C Pathogenic ★★★ same condition
BRCA2 c.475+1G>A Pathogenic ★★★ same condition
BRCA2 c.475+1G>T Pathogenic ★★★ same condition
BRCA2 c.476-2A>G Pathogenic ★★★ same condition
BRCA2 c.517-2A>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/brca2-c-1909-plus-1g-a (accessed [today's date]).

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