rs1800747
A SNP in the BRCA1 gene on chromosome 17. Its most notable genotype is C;T: BRCA1 pathogenic mutation associated with breast cancer
- Gene
- BRCA1
- Location
- Chr 1743,063,952 (GRCh38)
- Highest magnitude
- 6.0Very important
- Tested on
- 23andMe, AncestryDNA
Genotypes
Plus strand, as in 23andMe and AncestryDNA files.
- C;TMost notableBadBRCA1 pathogenic mutation associated with breast cancer
- G;GGoodNo summary available.
- C;GBadBRCA1 variant considered pathogenic for breast cancer
- C;CGoodcommon in clinvar
SNPedia records rs1800747 on the minus strand: (A;G), (C;C), (C;G), (G;G). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.
Related
Conditions, medicines and genes
Other BRCA1 SNPs
- rs28897696T;Tcarrier of two copies of BRCA1 variant; likely to be at high risk for breast/ovarian cancerVery important
- rs41286296A;CBRCA1 pathogenic mutation associated with breast cancerVery important
- rs62625306A;CBRCA1 pathogenic mutation associated with breast cancerVery important
- rs62625307A;GBRCA1 pathogenic mutation associated with breast cancerVery important
- i6051899A;Clikely to be BRCA1 variant pathogenic for breast cancerVery important
- rs28897672A;Tconsidered a pathogenic BRCA1 breast cancer variantVery important
- rs28897686A;CBRCA1 pathogenic mutation associated with breast cancerVery important
- rs28897698A;CBRCA1 variant considered pathogenic for breast cancerVery important
Notes
From SNPedia
Notes
rs1800747, also known as IVS17-1G>A, c.5075-1G>A and then also IVS17-1G>C and c.5075-1G>C, is a variant in the BRCA1 gene. The common G allele can mutate to all three possibilities: G>A, G>C, and G>T. All are rare. Currently the G>A and G>C alleles are considered pathogenic in ClinVar for breast cancer. In addition to rs1800747, this SNP is represented on 23andMe microarrays as i5009520 and i5009521, respectively, for the G>A and G>T alleles.
C;T
see discussion at rs1800747
C;G
see discussion at rs1800747
Source and license
Adapted from rs1800747 on SNPedia, using a snapshot taken October 16, 2026. SNPedia content is shared under CC BY-NC-SA 3.0 US, and this page is shared under the same license.
SNPedia is a community-edited wiki. Its entries can be incomplete, out of date or wrong, and nothing here is a diagnosis or medical advice. Magnitude is a community rating of how interesting a genotype is, not a risk score.