MacGregor's Syndrome is a terminal disease.
MacGregor's syndrome is a genetic defect that creates fluid buildup in the lungs, which leads to oxygen deprivation and multi-system organ failure. It was known to affect exdrug addicts. 
William Tockman, a former bank robber, suffered from MacGregor's Syndrome. However, rather than using the money he stole, he gave it to his sister. His plans were eventually stopped by Felicity Smoak.
Behind the scenes
- The fictional disease first appeared in the 1992 cartoon Batman: The Animated Series as a disease contracted by the supervillain Mr. Freeze's wife that forced Freeze to put her in suspended animation. The disease was not however named until the 1997 movie Batman & Robin. Mr. Freeze was working on a cure for his wife Nora before the accident. Later in the film, Alfred Pennyworth is revealed to also be suffering from the early stages of the disease.