trisomy

American  

[trahy-soh-mee] / ˈtraɪ soʊ mi /

noun

Pathology.

1. an abnormality characterized by the presence of an additional chromosome to the normal diploid number.

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trisomy British  

/ traɪˈsəʊmɪk, ˈtraɪsəʊmɪ /

noun

1. the condition of having one chromosome of the set represented three times in an otherwise diploid organism, cell, etc. Trisomy of chromosome 21 results in Down's syndrome

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trisomy Scientific  

/ trī-sō′mē,trī′sō′- /

1. The condition of having three copies of a given chromosome in each body cell rather than the normal number of two.

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Other Word Forms

• trisomic
  adjective

Etymology

Origin of trisomy

First recorded in 1925–30; tri- + -some ³ + -y ³

Example Sentences

See Examples For:

trisomy

Down syndrome is a genetic disorder caused by the presence of an extra copy of chromosome 21, also known as trisomy 21.

From Science Daily ● Feb. 27, 2024

But Down syndrome — also known as trisomy 21 — is a remarkably variable disease.

From New York Times ● Feb. 20, 2024

But tests confirmed late last month that the baby she was carrying had a condition called trisomy 18, an extra chromosome that made it likely the baby would die in utero or shortly after birth.

From Seattle Times ● Dec. 12, 2023

Up to 95 percent of infants born alive with trisomy 18 die during their first year of life.

From Salon ● Dec. 12, 2023

Kate Cox, who is 20 weeks pregnant with her third child, learned that her child had full trisomy 18, a genetic condition that is almost always fatal in utero or the first year after birth.

From Slate ● Dec. 8, 2023