plei·​ot·​ro·​py plī-ˈä-trə-pē How to pronounce pleiotropy (audio)
: the phenomenon of a single gene influencing two or more distinct phenotypic traits : the quality or state of being pleiotropic
In genetics, there's a concept called pleiotropy, which posits that a single gene can influence multiple traits. [Steven] Tanksley suggests there's substantial evidence that at least some domesticated fruits selected for greater size were also altered in shape because both traits were controlled by the same selected gene or set of genes.Scott LeFee

Examples of pleiotropy in a Sentence

Recent Examples on the Web The authors note that these extended life spans are part of what enabled them to find evidence for antagonistic pleiotropy in the genomic data. Diana Gitig, Ars Technica, 8 Dec. 2023 That’s via a process known as pleiotropy—the phenomenon in which one genetic locus affects two or more traits. Frederick Kaufman, Fortune, 30 July 2023 Antagonistic pleiotropy is particularly useful for medical researchers. Carl Zimmer, Discover Magazine, 15 Feb. 2011 This has lead to speculation on this weblog from commenters about pleiotropy between genes for height and intelligence, or height and I.Q. as independent signals for mutational load. Razib Khan, Discover Magazine, 19 May 2011 But that might be because it has been shaped by antagonistic pleiotropy. Carl Zimmer, Discover Magazine, 15 Feb. 2011 Not too surprising due to the relatively ubiquity of pleiotropy; one gene with many effects. Razib Khan, Discover Magazine, 13 Nov. 2013 There is no doubt that even simple genetic abnormalities may cause many phenotypic consequences; this is called pleiotropy. Jessica Riskin, The New York Review of Books, 21 Apr. 2022 Combine pleiotropy, the effect of one gene on multiple traits, with polygeny and epistasis, and the tangle of abstraction gets intractable very quickly. Razib Khan, Discover Magazine, 19 Jan. 2011

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'pleiotropy.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1921, in the meaning defined above

Time Traveler
The first known use of pleiotropy was in 1921

Dictionary Entries Near pleiotropy

Cite this Entry

“Pleiotropy.” Dictionary, Merriam-Webster, Accessed 16 Jun. 2024.

Medical Definition


plei·​ot·​ro·​py plī-ˈä-trə-pē How to pronounce pleiotropy (audio)
plural pleiotropies
: the quality or state of being pleiotropic
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