pleiotropy
noun
plei·ot·ro·py
plī-ˈä-trə-pē 
genetics
: 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
Scott LeFeeExamples of pleiotropy in a Sentence
Recent Examples on the Web
Marcin Klapczynski/Getty Images The researchers note that no pleiotropy—the production by a single gene of two or more apparently unrelated effects—was identified, strengthening the integrity of the findings and implying causation.
—Hannah Millington, MSNBC Newsweek, 12 Aug. 2025
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
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
Not too surprising due to the relatively ubiquity of pleiotropy; one gene with many effects.
—Razib Khan, Discover Magazine, 13 Nov. 2013
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Hannah Millington, MSNBC Newsweek, 12 Aug. 2025
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
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
Not too surprising due to the relatively ubiquity of pleiotropy; one gene with many effects.
—Razib Khan, Discover Magazine, 13 Nov. 2013
Cite this Entry
“Pleiotropy.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/pleiotropy. Accessed 9 Sep. 2025.
Copy CitationMedical Definition
pleiotropy
noun
plei·ot·ro·py
plī-ˈä-trə-pē
plural pleiotropies
: the quality or state of being pleiotropic
Love words? Need even more definitions?
Merriam-Webster unabridged
Share