How were the default gene-specific genetic test sensitivities in the CanRisk Tool chosen? 

The default genetic test sensitivities are described in Lee et al. 2022. These considered the technologies used at the time of the model development and allowances were made for possible Variants of Unknown Significance (not called as pathogenic) contributing to disease.

Genetic test sensitivities may vary across labs. If your genetic testing laboratory uses tests that are highly sensitive (e.g. including screening for large re-arrangements) and you believe the testing sensitivity is higher, then you can adjust the BRCA genetic test sensitivities in the CanRisk Tool to take account of that in risk calculations (see: How can I change the genetic test sensitivity?).