A disorder for people who swim too much. A true story, somewhere in Cape Town, South Africa where a person with the disorder suddenly produced gills at his neck and fins at his back though no organs were affected.
Possible symptoms of the disorder (Officially)
1. Has a "van" in his/her name
2. Prone to injuring her/him self whenever the person swims
3. Addicted to swimming too much, similar when a person has an orgasm.
Though not stated in the news, the worst case of the Christiaan Disorder was by an unfortunate swimmer, Christiaan van Zyl.