trisomy

[ trahy-soh-mee ]

noun

, Pathology.

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

trisomy

/ 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

trisomy

/ 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.

Derived Forms

• trisomic, adjective

Word History and Origins

Origin of trisomy¹

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

Word History and Origins

Origin of trisomy¹

C20: from tri- + ( chromo ) som ( e ) + -y ³

Example Sentences

Gina Kolata traveled to Utah to visit two families caring for babies with trisomy 18 and the doctor who counsels them.

From New York Times

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

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

From New York Times

They screen for chromosomal disorders such as trisomy 13 and 18, which often end in miscarriage or stillbirth, Down syndrome and extra or missing copies of sex chromosomes.

From Seattle Times

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