trisomy
noun
tri·so·my
ˈtrī-ˌsō-mē 
plural trisomies
: the condition (as in Down syndrome) of having one or a few chromosomes triploid in an otherwise diploid set
Examples of trisomy in a Sentence
Recent Examples on the Web
Testing, however, soon revealed trisomy 18, a genetic abnormality that is usually fatal, often before birth.
—
Peter Slevin, New Yorker, 1 Sep. 2025
Around 12 weeks into the pregnancy, doctors told Downs' sister, Tatum Green of Atlanta, the baby had a severe genetic condition called Edwards Syndrome or trisomy 18.
—Brad Schmitt, The Tennessean, 2 July 2025
That’s partly because, unlike a condition with a clear genetic marker like Down Syndrome or trisomy 18, ASD encompasses a wide range of conditions that share some characteristics.
—Laura Tillman, Hartford Courant, 16 June 2025
At a 14-week ultrasound, doctors saw an indicator of a genetic trisomy.
—Wendy Grossman Kantor, People.com, 10 June 2025
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Peter Slevin, New Yorker, 1 Sep. 2025
Around 12 weeks into the pregnancy, doctors told Downs' sister, Tatum Green of Atlanta, the baby had a severe genetic condition called Edwards Syndrome or trisomy 18.
—Brad Schmitt, The Tennessean, 2 July 2025
That’s partly because, unlike a condition with a clear genetic marker like Down Syndrome or trisomy 18, ASD encompasses a wide range of conditions that share some characteristics.
—Laura Tillman, Hartford Courant, 16 June 2025
At a 14-week ultrasound, doctors saw an indicator of a genetic trisomy.
—Wendy Grossman Kantor, People.com, 10 June 2025
See All Example Sentences for trisomy
Cite this Entry
“Trisomy.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/trisomy. Accessed 9 Sep. 2025.
Copy CitationMedical Definition
trisomy
noun
tri·so·my
ˈtrī-ˌsō-mē
plural trisomies
: the condition (as in Down syndrome) of having one or a few chromosomes triploid in an otherwise diploid set
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