Mayo Clinic Care Network Content
Definitions

Trisomy


Overview

Trisomy is a genetic disorder in which a person has 3 copies of a chromosome instead of 2. Examples of trisomy chromosomal disorders include trisomy 13, trisomy 18 and trisomy 21 (Down syndrome).

Symptoms

Trisomy can cause a variety of health conditions ranging from mild intellectual and developmental disability to shortened life expectancy.