rs1800709
A SNP in the BRCA1 gene on chromosome 17. Its most notable genotype is A;A: predisposition to breast cancer?
- Gene
- BRCA1
- Location
- Chr 1743,093,010 (GRCh38)
- Highest magnitude
- 2.0Worth knowing
- Tested on
- 23andMe, AncestryDNA, FamilyTreeDNA
- Minor allele frequency
- <1%
Genotypes
Plus strand, as in 23andMe and AncestryDNA files.
- G;GGoodnormal
- A;GNot ratedpossible predisposition to breast cancer
- C;CNot ratedNo summary available.
- A;AMost notableNot ratedpredisposition to breast cancer?
SNPedia records rs1800709 on the minus strand: (C;C), (C;T), (G;G), (T;T). Magnitude rates how notable a genotype is from 0 to 10, not how risky it is.
Frequency
Share of each genotype in 6 HapMap populations.
- AverageG;G 99% A;G 1% C;C 0% A;A 0%
- European ancestry (Utah)G;G 98% A;G 2% C;C 0% A;A 0%
- Han Chinese (Beijing)G;G 100% A;G 0% C;C 0% A;A 0%
- Japanese (Tokyo)G;G 99% A;G <1% C;C 0% A;A 0%
- Yoruba (Nigeria)G;G 100% A;G 0% C;C 0% A;A 0%
- African ancestry (Southwest US)G;G 98% A;G 2% C;C 0% A;A 0%
- Mexican ancestry (Los Angeles)G;G 97% A;G 4% C;C 0% A;A 0%
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
- rs1800747C;TBRCA1 pathogenic mutation associated with breast cancerVery important
- rs28897672A;Tconsidered a pathogenic BRCA1 breast cancer variantVery important
- rs28897686A;CBRCA1 pathogenic mutation associated with breast cancerVery important
Notes
From SNPedia
Show notes, about 150 words
rs41293463 is a SNP causing an amino acid change in the breast cancer 1 BRCA1 gene at amino position 841. The more common rs41293463(C) allele encodes Arg, while the rare rs41293463(T) allele encodes Trp; this SNP is also known as R841W. A 1996 study of 305 cases in Southern California of breast cancer and ovarian cancer found 3 cases carrying the rs1800709(T) allele. In all three cases, there was a strong family history of breast, ovarian, or other cancers, and family members showed a high concordance of cancer incidence with the presence of this SNP. However, the age of cancer onset was the same as for sporadic cases. The authors conclude that this SNP may explain around 1% (CI: 0-1.7%) of all breast and ovarian cancers, at least for this population. Note: this SNP is rather unlikely to be a causative or high penetrance mutation, given it's frequency in the population at large. * See also Omim 113705.0022
Source and license
Adapted from rs1800709 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.