60yearold woman who was diagnosed with breast cancer at age 36 and ovarian cancer at age 50 is being seen for genetic counseling. Her mother was diagnosed with breast cancer at age 55; a maternal aunt was diagnosed with ovarian cancer at age 60; and a maternal first cousin was diagnosed with leukemia at age 20. The proband underwent comprehensive germline sequence analysis of BRCA1 and BRCA2 at the time of her ovarian cancer diagnosis with negative results. Which of the following additional genetic tests would be MOST appropriate for the proband to have?
A. comprehensive germline large rearrangement analysis of BRCA1 and BRCA2
B. BRCA1 and BRCA2 promoter methylation analysis of either of her tumors
C. comprehensive germline PTEN genetic testing
D. P53 promoter methylation analysis of either of her tumors