This work describes the reasons and emotional responses of healthy descendants after counseling for presenilin mutations in early-onset familial Alzheimer's disease (EOFAD), tau mutations in familial frontotemporal dementia (FTD), and prion mutations in fatal familial insomnia (FFI). A multidisciplinary protocol following Huntington's disease counseling guidelines and a post-test follow-up program were developed to counsel healthy descendants of affected families. The psychological consequences, anxiety levels, and depression status were assessed through validated scales before and after disclosing the information. Nine people from three different families, one with EOFAD, another with FTD, and the other with FFI came for counseling. Their main reason for testing was to initiate early treatment in the future. Disclosing the information decreased anxiety in two carriers, increased it temporarily in one, and had no effect in another. All noncarriers felt relieved. Overall, after a mean of 30 months of follow-up, no negative psychological reactions were observed. All participants positively valued the program. Although preliminary, our observations suggest that predictive testing in EOFAD, FTD, and FFI is safe and may be of benefit when performed with a delicate approach under strict pretest counseling protocols and post-test follow-up programs. The emotional reactions were similar, although the diseases, their phenotype, and mutation characteristics were different.