Taggart's Syndrome was a neurological disorder which afflicted Humans. The disorder was known to usually cause death by the age of twenty. The only known treatment was Rigellian gene therapy. John Frederick Paxton, leader of the xenophobic group Terra Prime, suffered from this condition, and took regular injections to treat himself. Commander T'Pol later noted Paxton's hypocrisy for using an alien medical treatment, which conflicted with his beliefs of Human purity. (ENT: "Terra Prime")