A patient is 34 years old and concerned about possibly being a carrier for HNPCC because his father died of colon cancer at 39, his father's sister died of colon cancer at age 41, and his brother (aged 37) now has colon cancer. The brother's testing is negative for all the known mutations associated with inherited forms of colon cancer. How should this patient be counseled about his risk for colon cancer?
A)Explain that because the brother with cancer is negative for these gene mutations, this cancer is most likely sporadic, and his risk is the same as that for the general population.
B)Explain that he could benefit from testing even though his brother is negative for these mutations because reduced penetrance might account for his negative status.
C)Explain that testing for him would be of no benefit because of the current test limitations but that his family history does place him at high risk.
D)Explain that his risk is not related to his brother's diagnosis because he did not inherit any genes from him, but because his father is a first-degree relative, testing should be considered.

Question

Quizplus · Accepted Answer

Further testing for common mutations would be of no benefit to this patient. His risk is not known but should be considered high on the basis of family history. Although some of the more common single-gene mutations responsible for serious health problems have been identified, not all have been identified. In addition, some mutations may be specific for a family and not present in the general population. When a disorder can be identified by family history as following autosomal-dominant inheritance patterns, but no known mutation has been identified, all first-degree relatives should be managed in terms of surveillance, screening, and prophylaxis as if they had a known mutation.

A Patient Is 34 Years Old and Concerned About Possibly