A rare degenerative neurological condition, normally inherited, that the Ferengi Bok induces in Jason Vigo while rewriting his DNA to pass him off as Picard's son.
Forrester-Trent Syndrome appears in the Next Generation episode Bloodlines. The former DaiMon Bok announces that he will kill Jason Vigo, the son Picard never knew he had, and a genetic test aboard the Enterprise appears to confirm the relationship.
Jason then suffers a neurological seizure. Beverly Crusher diagnoses Forrester-Trent Syndrome, which can bring paralysis or death if untreated, and notes that it is hereditary; yet neither Picard nor Jason's mother Miranda Vigo carried it.
The inconsistency exposes the fraud. Crusher finds that Jason's DNA has been resequenced to mimic Picard's and that the syndrome is a side effect of the procedure. She is able to treat it, and Picard confronts Bok with the truth in front of his hired crew.