In this retrospective study, we have researched the psychological impact of pre-symptomatic testing (PST) for 2 autosomal dominant late-onset diseases: Huntington disease (HD and familial amyloidotic polyneuropathy (FAP) V30M TTR. The study included 53 subjects: 40 (75.5%) were the offspring at risk for FAP and 13 (24.5%) for HD. Of these, 38 (73.1%) received the carrier result and 12 (23.1%) the noncarrier result; 3 of them did not want to know the result. The indicators taken for emotional distress were the subscales and global indexes of psychopathological Behavior Symptoms Inventory (BSI), applied in the pre-test and post-test, one-year after notification of results. Values decreased significantly one year after the implementation of the PST, regardless of the studied disease or test result; this seems to corroborate previous studies showing that testing does not increase pre-symptomatic levels of emotional disturbance in individuals. However, the subjects studied showed, for all subscales and global indexes of the BSI, significantly higher values than those of control groups.