Dune Spoiler:
In the Dune series, all the Bene Gesserit undergo basically an overdoes of spice that unlocks genetic memory. This happens to Paul's sister, Alia, and his twins, Leto and Ghanima in the womb; all are pre-born and have access to the subjective experiences of all their genetic ancestors... matrilineally? The risk is abomination, in which one of those dated-memories takes control of the biologically original personality.