MSH6 and breast cancer: Two GPPs carrying MSH2 c.2684 C > T (p.Pro895Leu) had personal breast cancer history (*p = 0.017, OR = 117.8, 95% CI = 1.5), 13 GPPs carrying MSH6 c.3100 C > T (p.Arg1034Trp) (*p = 0.013, OR = 17.2, 95% CI = 1.4) or TSC2 c.2158 A > G (p.Lys720Glu) (*p = 0.019, OR = 12.9, 95% CI = 1.16) had personal history of tumor-related surgeries, and 6 GPPs carrying MSH2 c.641 G > T (p.Arg214Ile) (**p = 0.006, OR = 24.1, 95% CI = 2.2) reported parent’s history of cancer, or parent’s cause of death was cancer (Supplementary Table 1, Additional File 3).