If you think about how you use English words, you quickly realize that words are polyfunctional. “House,” for instance, can be a noun, a verb, or an adjective (“house music,” “house money,” etc.). 

Thus, if you imagine eliminating the word “house” from your daily-use lexicon, a wide range of different propositions would be affected, many having no apparent semantic relation to each other.

Genes and proteins are remarkably similar to natural-language words in this polyfunctional respect. For many decades, “pleiotropy” has been the term describing the multiple-system consequences of genetic mutations to a single locus, where the functional consequences can be wide-ranging, and often surprising in their diversity.

For more on the subject, here is an open access article at Nature Genetics: “Network expansion of genetic associations defines a pleiotropy map of human cell biology.”