BRCA1 c.5266dupC (5382insC) — Ashkenazi Jewish founder mutation
Deterministic view of the source YAML entity. Clinical authority remains with the cited source IDs and reviewer sign-off state.
| ID | BIO-BRCA1-ASHKENAZI-FOUNDER-5266DUPC |
|---|---|
| Type | Biomarker |
| Aliases | BRCA1 5266dupC founder mutationBRCA1 5382insCBRCA1 5385insCBRCA1 c.5266dupC (5382insC) — засновницька мутація ашкеназіc.5266dupc.5266dupC |
| Status | reviewed 2026-05-18 | pending_clinical_signoff |
| Diseases | None declared |
| Sources | SRC-NCCN-GENETIC-FAMILIAL-BREAST-OVARIAN-2025 |
Biomarker Facts
| Biomarker type | gene_mutation |
|---|---|
| Mutation details | {"exon": "20", "functional_impact": "loss_of_function", "gene": "BRCA1", "gene_hugo_id": "HGNC:1100", "hgvs_coding": "c.5266dupC", "hgvs_protein": "p.Gln1756ProfsTer74", "variant_type": "frameshift insertion (duplication)"} |
| Related biomarkers | BIO-BRCA1-BRCA2-GERMLINE |
Notes
Second of three Ashkenazi Jewish founder mutations. Single-nucleotide duplication (cytosine) in exon 20 causing frameshift and premature termination — truncates BRCA1 within the BRCT2 domain, abolishing C-terminal protein-binding function critical for homologous-recombination repair coordination. Also called 5382insC in legacy nomenclature (offset by stop-codon counting convention shift). Recurrent founder effect in AJ populations (~0.8-1.0% carrier frequency in AJ vs <0.1% non-AJ); also reported as a recurrent variant in Polish, Russian, Belarusian populations (likely separate founder events or AJ admixture). Lifetime cancer risks consistent with BRCA1 average. NCCN 2025 endorses population-wide AJ founder-panel testing (3-mutation panel) regardless of family history. Same surveillance and risk-reduction protocols as other BRCA1 pathogenic variants. STUB pending two-Co-Lead signoff.
Used By
No reverse references found in the YAML corpus.