A genetic pathway is the set of interactions occurring between a group of genes who depend on each other's individual functions in order to make the aggregate function of the network available to the cell. Commonly, pathways are shown using the same graphical conventions as graph theory with individual genes being presented as nodes or vertices in the image while the informational interactions between genes are indicated by drawn lines commonly referred to as graph edges or graph connections.
A genetic mutation disrupting the function of one gene in a pathway breaks the informational connection between genes acting before and after the mutant gene. Similar to a break in a phone line between two cities, it is often possible that the two groups of isolated genes will still have some within group communication even though they have lost the ability to have complete pathway activity.