--- title: "BRCA1 T1700A (c.5098A>G, rs397509227) | Dante Labs" description: "ClinVar classifies BRCA1 T1700A as Likely pathogenic (reviewed by expert panel). Where it sits in the genome, its predicted effect, and the Genome Test reports that look at it." url: "https://dantelabs.com/genes/brca1/variants/t1700a" --- 1. [Genes](https://dantelabs.com/genes) 2. [BRCA1](https://dantelabs.com/genes/brca1) 3. BRCA1 T1700A Variant # BRCA1 T1700A NM_007294.4(BRCA1):c.5098A>G (p.Thr1700Ala) Also known as - p.Thr1700Ala - p.T1700A - rs397509227 * ClinVar classification Likely pathogenic * Review status 3 stars out of 4 reviewed by expert panel * Last evaluated 18 August 2025 * Expert panel ClinGen ENIGMA BRCA1 and BRCA2 Variant Curation Expert Panel, ClinGen Data current to ClinVar release 2026-10-12 · Dante Labs data release 2026.10.16-c6eea6bf Facts last changed 16 October 2026 ## Summary T1700A is a missense variant in BRCA1: it changes a single amino acid in the protein the gene encodes. ClinVar classifies it as likely pathogenic for BRCA1-related cancer predisposition (reviewed by expert panel). ## ClinVar classifications | Condition | Classification | Review status | Submissions | Last evaluated | | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------- | ----------------------------------------- | ------------ | -------------- | | [BRCA1-related cancer predisposition](https://dantelabs.com/conditions/hereditary-breast-ovarian-cancer) [ClinVar VCV000055399 (opens in a new tab)](https://www.ncbi.nlm.nih.gov/clinvar/variation/55399/) | Likely pathogenic | 3 stars out of 4 reviewed by expert panel | 1 submission | 18 August 2025 | Classifications as ClinVar records them in release 2026-10-12. ClinVar updates them as evidence is reviewed. ## Where it lies in BRCA1 T1700A lies in exon 17 of the 23 in BRCA1's MANE Select transcript, NM_007294.4. [BRCA1 variants in exon 17 →](https://dantelabs.com/genes/brca1/variants?exon=17) [BRCA1's gene diagram →](https://dantelabs.com/genes/brca1#gene-structure) ## Molecular details | Gene | [BRCA1](https://dantelabs.com/genes/brca1) | | --------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------- | | Transcript | NM_007294.4 MANE Select | | Coding DNA change (HGVS c.) | c.5098A>G | | Protein change (HGVS p.) | p.Thr1700Ala p.T1700A | | Predicted consequence | Missense [missense_variant (opens in a new tab)](https://purl.obolibrary.org/obo/SO_0001583) | | Predicted impact | Moderate | | Position (GRCh38) | chr17:43063928 T>C | | Position (GRCh37) | chr17:41215945 T>C | | dbSNP ID | [rs397509227 (opens in a new tab)](https://www.ncbi.nlm.nih.gov/snp/rs397509227) | | ClinVar Variation ID | [VCV000055399 (opens in a new tab)](https://www.ncbi.nlm.nih.gov/clinvar/variation/55399/) | | ClinVar Allele ID | 70066 | | ClinGen Allele Registry ID | [CA003238 (opens in a new tab)](https://reg.clinicalgenome.org/redmine/projects/registry/genboree_registry/by_canonicalid?canonicalid=CA003238) | | ClinVar name | NM_007294.4(BRCA1):c.5098A>G (p.Thr1700Ala) | ## BRCA1 T1700A in other databases - [ClinVar VCV000055399 (opens in a new tab)](https://www.ncbi.nlm.nih.gov/clinvar/variation/55399/) - [dbSNP rs397509227 (opens in a new tab)](https://www.ncbi.nlm.nih.gov/snp/rs397509227) - [ClinGen Allele Registry CA003238 (opens in a new tab)](https://reg.clinicalgenome.org/redmine/projects/registry/genboree_registry/by_canonicalid?canonicalid=CA003238) - [gnomAD 17-43063928-T-C (opens in a new tab)](https://gnomad.broadinstitute.org/variant/17-43063928-T-C?dataset=gnomad_r4) - [Ensembl rs397509227 (opens in a new tab)](https://www.ensembl.org/Homo_sapiens/Variation/Explore?v=rs397509227) ## Reports that look at this variant (1) These Genome Test condition reports include T1700A among the variants they look at. | Report | Conditions | Inheritance | | ------------------------------------------------------------------------------------------------------------------- | ----------------------------------- | ------------------ | | [Hereditary Breast and Ovarian Cancer (BRCA1/2)](https://dantelabs.com/conditions/hereditary-breast-ovarian-cancer) | BRCA1-related cancer predisposition | Autosomal dominant | ## Other variants in BRCA1 - [A92Ffs\*4 Pathogenic 3 stars out of 4](https://dantelabs.com/genes/brca1/variants/a92ffs4) - [A134Qfs\*7 Pathogenic 3 stars out of 4](https://dantelabs.com/genes/brca1/variants/a134qfs7) - [A302Cfs\*2 Pathogenic 3 stars out of 4](https://dantelabs.com/genes/brca1/variants/a302cfs2) - [A302Lfs\*12 Pathogenic 3 stars out of 4](https://dantelabs.com/genes/brca1/variants/a302lfs12) - [A322Kfs\*2 Pathogenic 3 stars out of 4](https://dantelabs.com/genes/brca1/variants/a322kfs2) - [A322Lfs\*19 Pathogenic 3 stars out of 4](https://dantelabs.com/genes/brca1/variants/a322lfs19) - [A407Sfs\*5 Pathogenic 3 stars out of 4](https://dantelabs.com/genes/brca1/variants/a407sfs5) - [A433Pfs\*8 Pathogenic 3 stars out of 4](https://dantelabs.com/genes/brca1/variants/a433pfs8) - [A469Qfs\*6 Pathogenic 3 stars out of 4](https://dantelabs.com/genes/brca1/variants/a469qfs6) - [A521X Pathogenic 3 stars out of 4](https://dantelabs.com/genes/brca1/variants/a521x) [All BRCA1 variants](https://dantelabs.com/genes/brca1/variants) ## Limitations This page describes publicly available information about a genetic variant. It is not a diagnosis, and it says nothing about whether you or anyone else carries this variant. Classifications come from ClinVar and change as new evidence is reviewed. A classification here may differ from the one in ClinVar today, or from the one a laboratory reports. Whole genome sequencing with short reads can miss or miscall some variants, particularly in repeated or highly similar stretches of DNA and in large insertions, deletions or rearrangements. If you have questions about a variant in your own results or in your family, talk to a genetic counsellor or your doctor. ## Sources & credits - Classifications from ClinVar (release 2026-10-12), National Center for Biotechnology Information. - Condition terms from the Mondo Disease Ontology (release 2026-10-06), used under CC BY 4.0. - Gene symbols and names from the HUGO Gene Nomenclature Committee (release 2026-10-16). - Allele identifiers from the ClinGen Allele Registry (release 2026-10-16-c4908f54). - Reference SNP identifiers from dbSNP (release b157), National Center for Biotechnology Information. - Gene–disease links from the Gene Curation Coalition, GenCC (release 2026-10-16). - Difficult regions from the Genome in a Bottle Consortium (release v3.6). - Transcripts from MANE (release v1.5), NCBI and EMBL-EBI. - Predicted consequences from mehari (release 0.11.0), with transcript models from cdot. - Built from Dante Labs data release 2026.10.16-c6eea6bf of 16 October 2026. ## Cite this page APA > Dante Labs. (16 October 2026). BRCA1 T1700A (c.5098A>G, rs397509227) (Version 2026.10.16-c6eea6bf). Retrieved 16 October 2026, from https\://dantelabs.com/genes/brca1/variants/t1700a Vancouver > Dante Labs. BRCA1 T1700A (c.5098A>G, rs397509227) \[Internet]. Version 2026.10.16-c6eea6bf. 16 October 2026 \[cited 16 October 2026]. Available from: https\://dantelabs.com/genes/brca1/variants/t1700a Download citation [RIS](https://dantelabs.com/genes/brca1/variants/t1700a/cite.ris) [BibTeX](https://dantelabs.com/genes/brca1/variants/t1700a/cite.bib) [CSL-JSON](https://dantelabs.com/genes/brca1/variants/t1700a/cite.json) ## Read your whole genome From $449 Free shipping · Results in 6–8 weeks [Explore the Genome Test](https://dantelabs.com/whole-genome-sequencing)