# NM_000059.4(BRCA2):c.8971C>T (p.Arg2991Cys)

https://sugi.bio/variant/brca2-p-arg2991cys

## Summary

**BRCA2 p.Arg2991Cys (c.8971C>T)** is classified **Conflicting classifications of pathogenicity** in BRCA2 (ClinVar, Conflicting submitters, 7 submitters; last evaluated 2026-03-19). AlphaMissense: likely benign (0.2026); Very rare (popmax 0.00446%, eas); Associated with hereditary neoplastic syndrome.

**At a glance:** Conflicting classifications of pathogenicity · review: Conflicting submitters · rsID rs751787816 · 7 submitters · 4 linked conditions · AlphaMissense likely benign · very rare (popmax 0.00446%, eas)

## For patients & families {#patients}

This is a change in the BRCA2 gene that is of uncertain or conflicting significance (submitters disagree on it), submitted by 7 submitters, and is linked to hereditary neoplastic syndrome.

*Reference information, not medical advice, and not a prediction for any individual. A genetic counselor or clinician can interpret what it means for you and your family.*

|  |  |
| --- | --- |
| Clinical trials | 31 registered for this condition — see ClinicalTrials.gov |

**Support & next steps:** [Condition overview & support (NIH GARD)](https://rarediseases.info.nih.gov/diseases/0019921/index) · [Find a genetic counselor (NSGC)](https://findageneticcounselor.nsgc.org/).

## Identity {#identity}

| Field | Value |
| --- | --- |
| Gene | [BRCA2](https://sugi.bio/atlas/gene/BRCA2/) |
| Protein change (HGVS p.) | p.Arg2991Cys |
| Coding change (HGVS c.) | c.8971C>T |
| MANE Select transcript | [NM_000059](https://www.ncbi.nlm.nih.gov/nuccore/NM_000059) |
| dbSNP | [rs751787816](https://www.ncbi.nlm.nih.gov/snp/rs751787816/) |
| Variant type | single nucleotide variant |
| Location | chr13:32379767-32379767 (GRCh38) |
| ClinVar | [VCV489793](https://www.ncbi.nlm.nih.gov/clinvar/variation/489793/) |

**All HGVS expressions:** `LRG_293:g.69288C>T`, `LRG_293t1:c.8971C>T`, `NC_000013.10:g.32953904C>T`, `NC_000013.11:g.32379767C>T`, `NG_012772.3:g.69288C>T`, `NM_000059.4:c.8971C>T`

## Computational & population evidence {#evidence}

**Concordance:** Mixed / partial computational evidence (see below).

- AlphaMissense **likely benign** (0.2026)
- REVEL 0.555 (indeterminate)
- Conservation: phyloP 2.704, GERP 1.59, phastCons 1 — highly conserved (differs from AlphaMissense)
- **SaProt:** not scored — SaProt is structure-aware and AlphaFold DB has no model for this protein. That is a property of the dataset, not of the variant, and is not evidence either way.
- CADD: **PHRED 25.3**. No single ClinGen-calibrated threshold exists and the expert panels that use CADD disagree — GUCY2D/AIPL1 require ≥ 20.0 for an untranslated-region variant, ABCA4 ≥ 28.1 for a synonymous or indel variant, the Pulmonary Hypertension panel imports Pejaver 2022's missense-calibrated numbers, and the Antibody Deficiencies panel declines CADD entirely for PIK3CD. CADD v1.7 also incorporates Zoonomia phyloP, so it partly re-expresses the conservation above. *Descriptive; no threshold applied.*
- Regional missense constraint: **o/e 0.87** across the covering region of the MANE Select transcript (32,363,510–32,398,767), spanning 35,257 bp. Chi-square p 0.00024. Describes the region, not this allele; gnomAD v4.1.1's own constrained determination. *Descriptive; no ACMG code applied.*
- SpliceAI: **below the reporting threshold**. This position is scored for a different substitution (C>G, Δ0.27 acceptor loss), so this allele was evaluated and its deltas all fell under Δ0.2 — a prediction of no splicing effect for this allele, not a gap in our data. *No ACMG code assigned.*
- Pangolin: Δ**0.20** (loss), gain 0.10 / loss 0.20. SpliceAI below 0.2. An independent predictor to SpliceAI — a different model trained on different data. *Descriptive; ClinGen's SVI calibration covers SpliceAI, not Pangolin, so no ACMG code is assigned.*
- Population frequency (gnomAD v4.1): grpmax **0.00446%** (eas) · FAF95 0.000739% · FAF99 0.000277% · 2/44,836 in the highest group · 5/1,611,520 alleles overall — very rare (popmax 0.00446%, eas).

| Ancestry group | Allele frequency | 1 in |
| --- | --- | --- |
| East Asian (grpmax) | 0.00446% | 22,418 |
| Remaining individuals (not grpmax-eligible) | 0.0016% | 62,408 |
| European (non-Finnish) | 0.00017% | 588,862 |

*Computational predictors are not independent (ClinGen Variant Classification guidance): AlphaMissense (Cheng et al. 2023) carries the ACMG weight for missense and conservation (phyloP/GERP/phastCons) for non-missense; REVEL (Pejaver-2022 calibrated strength bands) and SaProt (Su et al. 2023, structure-aware, ClinVar-independent protein language model, raw LLR) are shown as orthogonal agreement signals, not additive. For frequency, the gnomAD v4.1 grpmax filtering allele frequency (FAF95) is ClinGen's designated BA1/BS1 input (gnomAD v4 guidance v3.0, June 2025); BA1/BS1 thresholds are disease-specific, not a blanket 5%. Predictions, not a clinical determination.*

## Gene constraint & dosage {#gene-context}

**BRCA2** population constraint: LOEUF 0.803, pLI 6.5274e-44, missense-Z 1.0218; ClinGen dosage — haploinsufficiency 3/3, triplosensitivity 0/3. *Lower LOEUF and higher pLI indicate a gene that tolerates loss-of-function poorly; ClinGen dosage is the curated haploinsufficiency call.*

Curated gene–disease validity (ClinGen):

- **Fanconi anemia complementation group D1** — Definitive (AR)
- **BRCA2-related cancer predisposition** — Definitive (AD)

## Protein context {#protein}


**14 experimental structure(s)** (PDB): [1N0W](https://www.rcsb.org/structure/1N0W), [3EU7](https://www.rcsb.org/structure/3EU7), [6GY2](https://www.rcsb.org/structure/6GY2), [6HQU](https://www.rcsb.org/structure/6HQU), [7BDX](https://www.rcsb.org/structure/7BDX), [7LDG](https://www.rcsb.org/structure/7LDG) — incl. mutant structure 6HQU.

## What this gene does {#gene-function}

*Describes the biological roles of BRCA2 (the gene this variant disrupts) — not effects measured for this specific variant. A damaging variant is expected to affect these functions and pathways; the degree depends on the variant.*

**How this variant is thought to act:** BRCA2's established molecular role includes protease binding. In Reactome, BRCA2 is annotated in disease pathway(s) including **Defective HDR through Homologous Recombination Repair (HRR) due to PALB2 loss of BRCA1 binding function**, **Defective HDR through Homologous Recombination Repair (HRR) due to PALB2 loss of BRCA2/RAD51/RAD51C binding function**.

**Disease mechanism (Reactome):** BRCA2 loss or alteration is curated in [Defective HDR through Homologous Recombination Repair (HRR) due to PALB2 loss of BRCA1 binding function](https://reactome.org/content/detail/R-HSA-9704331), [Defective HDR through Homologous Recombination Repair (HRR) due to PALB2 loss of BRCA2/RAD51/RAD51C binding function](https://reactome.org/content/detail/R-HSA-9704646), [Defective homologous recombination repair (HRR) due to BRCA1 loss of function](https://reactome.org/content/detail/R-HSA-9701192).

### Pathways affected {#pathways}

BRCA2 participates in **14 Reactome pathways** (⚕ = disease pathway):

| Pathway (Reactome) | Evidence |
| --- | --- |
| ⚕ [Defective HDR through Homologous Recombination Repair (HRR) due to PALB2 loss of BRCA1 binding function](https://reactome.org/content/detail/R-HSA-9704331) | curated |
| ⚕ [Defective HDR through Homologous Recombination Repair (HRR) due to PALB2 loss of BRCA2/RAD51/RAD51C binding function](https://reactome.org/content/detail/R-HSA-9704646) | curated |
| ⚕ [Defective homologous recombination repair (HRR) due to BRCA1 loss of function](https://reactome.org/content/detail/R-HSA-9701192) | curated |
| ⚕ [Impaired BRCA2 binding to PALB2](https://reactome.org/content/detail/R-HSA-9709603) | curated |
| ⚕ [Impaired BRCA2 binding to RAD51](https://reactome.org/content/detail/R-HSA-9709570) | curated |
| ⚕ [Impaired BRCA2 binding to SEM1 (DSS1)](https://reactome.org/content/detail/R-HSA-9763198) | curated |
| ⚕ [Impaired BRCA2 translocation to the nucleus](https://reactome.org/content/detail/R-HSA-9709275) | curated |
| [HDR through Homologous Recombination (HRR)](https://reactome.org/content/detail/R-HSA-5685942) | curated |
| [HDR through MMEJ (alt-NHEJ)](https://reactome.org/content/detail/R-HSA-5685939) | curated |
| [Homologous DNA Pairing and Strand Exchange](https://reactome.org/content/detail/R-HSA-5693579) | curated |
| [Presynaptic phase of homologous DNA pairing and strand exchange](https://reactome.org/content/detail/R-HSA-5693616) | curated |
| [Resolution of D-loop Structures through Holliday Junction Intermediates](https://reactome.org/content/detail/R-HSA-5693568) | curated |
| [Resolution of D-loop Structures through Synthesis-Dependent Strand Annealing (SDSA)](https://reactome.org/content/detail/R-HSA-5693554) | curated |
| [Meiotic recombination](https://reactome.org/content/detail/R-HSA-912446) | electronic |

### Molecular function & processes (GO — experimentally supported) {#go}

**Molecular function:** protease binding, single-stranded DNA binding, histone H3 acetyltransferase activity, histone H4 acetyltransferase activity, identical protein binding, gamma-tubulin binding.

**Biological process:** double-strand break repair via homologous recombination, nucleotide-excision repair, double-strand break repair, negative regulation of mammary gland epithelial cell proliferation, positive regulation of DNA-templated transcription, centrosome duplication.

## Clinical significance {#significance}

**Conflicting classifications of pathogenicity** — review status Conflicting submitters *(criteria provided, conflicting classifications)*, last evaluated 2026-03-19.

**Submitter consensus:** conflicting (3 Uncertain significance, 2 Likely benign, 1 Uncertain Significance, 1 Benign).

**Submission history:** 7 submissions (2019–2026); classifications have differed over time.

### Submitter classifications {#submitters}

| Submitter | Classification | Review | Method | Date |
| --- | --- | --- | --- | --- |
| All of Us Research Program, National Institutes of Health | Uncertain Significance | criteria provided, single submitter | clinical testing | 2023-12-18 |
| Ambry Genetics | Likely benign | criteria provided, single submitter | clinical testing | 2019-12-06 |
| Department of Pathology and Laboratory Medicine, Sinai Health System | Uncertain significance | criteria provided, single submitter | clinical testing | 2022-04-11 |
| Color Diagnostics, LLC DBA Color Health | Uncertain significance | criteria provided, single submitter | clinical testing | 2023-11-21 |
| Labcorp Genetics (formerly Invitae), Labcorp | Uncertain significance | criteria provided, single submitter | clinical testing | 2025-11-27 |
| Center for Genomic Medicine, Rigshospitalet, Copenhagen University Hospital | Benign | criteria provided, single submitter | clinical testing | 2025-12-29 |
| Dasa | Likely benign | criteria provided, single submitter | clinical testing | 2026-03-19 |

## Associated conditions {#conditions}

[hereditary neoplastic syndrome](https://sugi.bio/atlas/disease/hereditary-neoplastic-syndrome/), [hereditary breast ovarian cancer syndrome](https://sugi.bio/atlas/disease/hereditary-breast-ovarian-cancer-syndrome/), [breast-ovarian cancer, familial, susceptibility to, 2](https://sugi.bio/atlas/disease/breast-ovarian-cancer-familial-susceptibility-to-2/), [BRCA2-related cancer predisposition](https://sugi.bio/atlas/disease/brca2-related-cancer-predisposition/).

**Reported phenotype names (ClinVar):** Hereditary cancer-predisposing syndrome, Hereditary breast ovarian cancer syndrome, Breast-ovarian cancer, familial, susceptibility to, 2, BRCA2-related cancer predisposition, not specified, AllHighlyPenetrant, Hereditary Cancer Syndrome, Tumor predisposition, Neoplastic Syndromes, Hereditary, Hereditary neoplastic syndrome.

## Similar variants {#similar}

Related BRCA2 variant pages (same residue, condition, or type): [BRCA2 p.Arg2991Pro](/variant/brca2-p-arg2991pro), [BRCA2 p.Arg2991=](/variant/brca2-p-arg2991), [BRCA2 p.Arg2991His](/variant/brca2-p-arg2991his), [BRCA2 p.Arg2991Leu](/variant/brca2-p-arg2991leu), [BRCA2 c.316+1G>T](/variant/brca2-c-316-plus-1g-t), [BRCA2 c.316+2T>C](/variant/brca2-c-316-plus-2t-c), [BRCA2 c.316+5G>A](/variant/brca2-c-316-plus-5g-a), [BRCA2 c.316+5G>C](/variant/brca2-c-316-plus-5g-c).

### Data sources & attribution {#sources}

ClinVar (NCBI — public domain, built 2026-10-14); gnomAD v4.1 (Broad Institute, built 2026-10-14); AlphaMissense (Cheng et al. 2023, © Google DeepMind — CC BY 4.0, built 2026-01-27); REVEL (Ioannidis et al. 2016 — ODbL, built 2026-07-13); SaProt (Su et al. 2023 — MIT, built 2026-10-14); SpliceAI (Illumina — free for non-commercial use, built 2026-10-13); CADD (Rentzsch et al. 2019, University of Washington — free for non-commercial use, built 2026-10-10); Conservation (phyloP/phastCons/GERP) (UCSC hg38 470-way mammal (Hiller Lab) + Ensembl Compara, built 2026-07-12); gnomAD Non-coding Constraint (Gnocchi) (Chen et al. 2024, Broad Institute — CC0, built 2026-10-11); gnomAD Regional Missense Constraint (Broad Institute — CC0, built 2026-10-13); Pangolin (Zeng & Li 2022 — CC BY 4.0, built 2026-10-11); Repeat regions (UCSC — RepeatMasker, TRF, segmental duplications, built 2026-10-11); ClinGen (ClinGen, built 2026-09-22); UniProt (CC BY 4.0); Reactome / GO (CC BY 4.0, built 2026-09-23); MaveDB (per-record license, built 2026-10-11); CIViC (CC0, built 2026-09-22); Orphanet (Orphanet, built 2026-06-12)

*Primary record: NCBI ClinVar (variation 489793). Classifications reflect these databases as of the page's build date and may change. Free reference use — not medical advice; consult the primary submitters and a clinician.*