A painful degenerative brain disease that killed the warp engineer Henry Archer, and which his son Jonathan believes genetic engineering could have cured.
Clarke's Disease is mentioned in the Enterprise episode Cold Station 12. While pursuing the geneticist Arik Soong and his Augments, Jonathan Archer says that his father Henry died of the disease when Jonathan was a boy.
The illness left Henry Archer confused and in pain towards the end, at times unable to recognise his family. He did not live to see his warp five engine fly.
Archer raises it in the context of Earth's ban on genetic engineering, imposed after the Eugenics Wars. He admits that the techniques Soong champions might have saved his father, which leaves him unable to dismiss the scientist's arguments outright even while he hunts the Augments Soong raised.