ESR1 and breast cancer: Genotyping C325G in ESR1 in breast cancer patients (n = 100) in comparison to healthy controls (n = 90) revealed a significant association of breast cancer risk in women 50 years and younger who had the C allele (OR: 2.28, 95% CI: 1.104.72) (P = 0.03) suggesting that polymorphism within the low penetrance ESR1 is associated with breast cancer susceptibility in young Sudanese women 31.