EHML only affects males, so Sara Murphy, Milo's older sister, is unaffected by it. The Murphy's Law 'gene' was transmitted for generations until Milo finally received it. This caused Milo to cheer for the opposing team only so that the Gecko's could win and not be affected by Murphy's law. It can also affect sports games as the team a person affected by it cheers for will not score points while the team that isn't cheered for will score points.
The Murphys find that the best way to deal with their condition is to approach life with a positive and optimistic attitude. Murphy's Law has extreme social consequences on whoever has it: most people familiar with the effects of the law will stay away from the afflicted. The idea of 'bad luck' as seen in the series leads to destructive events.
The basic idea of the hereditary disease is simple: it causes continuous catastrophes among members of the Murphy family. Murphy's Law is a condition which affects the Murphy family, as well as the main premise of Milo Murphy's Law.
