Rs55770810

rs55770810, also known as R1699W, is a SNP in the BRCA1 gene. The more common (C) allele encodes the amino acid arginine (R), while the rare (T) allele encodes a tryptophan (W).

An analysis of sequence variants of unknown clinical significance in the BRCA1 and BRCA2 genes concluded that this SNP was among the top 10 (over both genes) likely to lead to breast cancer, with a calculated odds of over 1,000:1 against this just being a spurious association. Although the clinical importance has not been proven, this may still be of use for genetic counseling.

This SNP is also represented on 23andMe microarrays as i5010082.