Is BRCA2 p.Asn20Ser (c.59A>G) pathogenic?

BRCA2 p.Asn20Ser (c.59A>G) is classified Conflicting classifications of pathogenicity in BRCA2 (ClinVar, Conflicting submitters, 8 submitters; last evaluated 2025-05-05). AlphaMissense: likely benign (0.0597); Very rare (popmax 0.00439%, sas); Associated with BRCA2-related cancer predisposition.

What condition is associated with BRCA2 p.Asn20Ser (c.59A>G)?

BRCA2 p.Asn20Ser (c.59A>G) is associated with BRCA2-related cancer predisposition, hereditary breast ovarian cancer syndrome, breast-ovarian cancer, familial, susceptibility to, 2 (ClinVar).

How common is BRCA2 p.Asn20Ser (c.59A>G) in the general population?

BRCA2 p.Asn20Ser (c.59A>G) is very rare (popmax 0.00439%, sas) (gnomAD).

What do computational predictors say about BRCA2 p.Asn20Ser (c.59A>G)?

AlphaMissense predicts likely benign (score 0.0597) — an in-silico prediction, not a clinical call.

BRCA2 p.Asn20Ser

c.59A>G · rs398122544 · VCV91433

Conflicting classifications of pathogenicity Conflicting submitters

Classification

Conflicting classifications of pathogenicity

ClinVar

Review

Conflicting submitters ★☆☆☆

ClinVar · 8 submitters

AlphaMissense

likely benign

0.0597 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.00439%, sas)

Missense predictors

0/2 damaging

AlphaMissense, REVEL · SaProt no call

Conditions

BRCA2-related cancer predisposition

Computational evidence

Protein change
AlphaMissense	0.0597	likely benign
REVEL	0.06	moderately benign-leaning
SaProt	—	not scored · why
⇒ AlphaMissense and REVEL both call this tolerated; SaProt makes no call.
Splicing
SpliceAI	<0.2	no splice effect predicted · four deltas, not one · how we know
Constraint at this position
Conservation	phyloP 0.095	GERP -2.4, phastCons 0.001
Regional constraint	o/e 1.03	unconstrained · MANE · 47 kb · p 0.059 · regional, not allelic
Overall
CADD	2.02	PHRED · no single calibrated threshold — expert panels disagree

AlphaMissense carries the ACMG weight for missense; REVEL is an independent agreement signal.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00439% South Asian · 4/91,074 alleles

Filtering AF 0.00143% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.000891%

Overall 0.00031% 5/1,613,880 alleles · very rare exomes 5/1,461,510 · genomes 0/152,370 · joint denominator

Ancestry group	Frequency	1 in
South Asiangrpmax	0.00439%	22,769
European (non-Finnish)	8.48e-05%	1,179,736

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
Protein: p.Asn20Ser
Coding: c.59A>G
MANE Select: NM_000059
dbSNP: rs398122544
Type: single nucleotide variant
Location: chr13:32316519 (GRCh38)
Gene constraint: LOEUF 0.803 · pLI <0.01 · ClinGen HI 3/3 (gnomAD)
Residue 20: the 'interaction with palb2' region

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

Disease context

Also linked: hereditary breast ovarian cancer syndrome breast-ovarian cancer, familial, susceptibility to, 2 hereditary neoplastic syndrome hereditary breast carcinoma

Similar variants

BRCA2 p.Asn20= Likely benign ★★ same residue
BRCA2 p.Asn20Asp Uncertain significance ★ ⚠ same residue
BRCA2 p.Asn20delinsSerLeuGlnTer Pathogenic ★ same residue
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

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-p-asn20ser (accessed [today's date]).

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