BRCA1 and breast cancer: Correlations between the individual standardized overall BC and ER- BC PRSs were considerably lower in comparison, but also statistically significant (BRCA1 PV carriers: ρ=0.54 (95% CI: 0.43–0.63); BRCA2 PV carriers: ρ=0.46 (95% CI: 0.30–0.60), Fig. 1).