While the lifetime risk in the general population is just below 1%, it is 6.5% in first-degree relatives of patients and it rises to more than 40% in monozygotic twins of affected people. Analyzing classic studies of the genetics of schizophrenia done as early as in 1930s, Fischer concludes that a concordance rate for psychosis of about 50% in monozygotic twins seems to be a realistic estimate, which is significantly higher than that in dizygotic twins of about 10–19% (ncbi.nlm.nih.gov/pmc/articles/PMC4623659/#ref3)

Inheritance pattern is autosomal dominant. Patient has 50% chance of inheriting and if she does inherit it, she has about 100% of developing colon cancer. 0.5 x 1 = 0.5 thus, 50% chance.