How do heredity and inheritance relate to the data presented in these charts? BRCA1 mutation BRCA2 mutation No BRCA mutation Total

Number of patients 89 35 318 442

Average age at diagnosis 43.9 46.2 50.4

Preventive mastectomy* 6 3 14 23

Preventive oophorectomy* 38 7 22 67

Number of deaths 16 1 21 38

Percent died 18 2.8 6.9 8.6

*A mastectomy is the surgical removal of one or both breasts, either partially or fully. An oophorectomy is the surgical removal of an ovary or ovaries.