Given that in order to determine clear criteria for genetic testing, we must first identify the likelihood of finding mutations in different populations, here we report our analysis of PALB2 in 175 breast and ovarian cancer pedigrees from a clinical cohort in Eastern Ontario, Canada, in which BRCA1 and BRCA2 testing failed to identify any causal variants. The gene discussed is PALB2; the disease is ovarian carcinoma.