What is the difference between a mutation search and a direct gene test?

A mutation search involves reading large parts of the gene, whereas a predictive or direct gene test is an analysis for a known mutation in a family. The CanRisk Tool distinguishes between these two types of genetic test on the basis of their sensitivity. For example, the risk models used by the CanRisk Tool assume that, by default, mutation searches only detect 90% of BRCA1 mutations, whereas direct gene tests are assumed to be 100% sensitive. As a result, the tool allows for the possibility that a mutation has been missed by a mutation search. 

You can specify different mutation search sensitivities prior to running a risk calculation in the 'Advanced Options' menu in the 'Family History' section.