23andMe, a leading personal genetics company, has identified seven single nucleotide polymorphisms (SNPs) significantly associated with breast size using its unique online research platform, and three of these SNPs are also associated with breast cancer in the Genome-Wide Association Study (GWAS) published online by BMC Medical Genetics. These findings are the first specific genetic link between breast size and risk of breast cancer. The study was derived by analyzing data from 16,175 European women who used 23andMe. The study linked these women’s bra cup sizes as well as bra band sizes to millions? s of genetic data on single nucleotide polymorphisms were compared. The analysis also adjusted for age, genetic history, breast cancer surgery, breastfeeding status and pregnancy history. According to Anne Wojcicki, CEO and co-founder of 23andMe, “23andMe is a very powerful resource platform for discovering new genes, and this study shows that important scientific insights can come from the unlikeliest of places.” And Wojcicki added, “Nearly 90 percent of our more than 150,000 users have participated in our online studies, making 23andMe faster and more effective than traditional research models. While some factors such as breast shape, such as breast texture, are directly related to breast cancer, the link between breast size and breast cancer is not clear. Although breast size is inherited, this study is the first to identify genetic polymorphisms between individuals with different breast sizes. The findings of this study by the study’s first author, Nicholas Eriksson, M.D., suggest that the same biological mechanisms exist between normal breast development and breast cancer.” Several studies have found that young women with larger breasts have a slightly increased risk of breast cancer. Our research on genetic factors also supports the idea that breast size is associated with the development of breast cancer. The newly identified loci associated with breast size are rs7816345 near ZNF703, rs4849887 and rs17626845 at both ends of INHBB, rs2173570 near ESR1, rs7089814 at ZNF365, rs12371778 near PTHLH, and rs62314947 located near AREG. The genetic polymorphisms of two of all these were strongly associated with breast cancer-related genetic polymorphisms (i.e., loci located in ESR1 versus PTHLH), while the third locus, ZNF365, was another locus associated with breast cancer genetic polymorphisms. The other three loci (ZNF703, INHBB and AREG) were strongly associated with estrogen regulation and breast development. Eeiksson concluded that “these findings provide a basis for studying the genetic factors underlying normal breast development, and some of these genes have also been shown to be associated with breast cancer. Although these findings do not directly support the correlation between breast size and breast cancer in existing epidemiological studies, this article contributes to a better understanding of the subtle interactions between breast shape and breast cancer risk.” The data from these studies on the breast size/breast cancer link came about thanks to the strong local jurisprudential support provided by 23andMe, which combined self-reported data from a web-based questionnaire with a broad range of genetic phenotypes obtained from genotype data from self-collected saliva samples. 23andMe first published evidence for this study in the journal PLoS in June 2010, noting the correlation of unusual traits such as loss of smell in asparagus and the sneeze reflex of photoreceptors and replication with other common genetic traits, two new genes associated with Parkinson’s disease in the journal PLoS Genetics, and in In April 2012, 23andMe published in PLoSONE five new significant genetic associations with genome-wide polymorphisms in the largest known association study for hypothyroidism to date. More recently 23andMe Magazine published another article in PLoS Genetics about the genetic correlates of male pattern baldness, some of which are associated with Parkinson’s disease and prostate cancer.