Home > Encyclopedia of Children's Health > Turner Syndrome

Definition

Turner syndrome is a birth defect caused by the absence of an X chromosome in some or all cells of a female, which inhibits sexual development and usually causes infertility.

Description

Chromosomes are structures in the nucleus of every cell in the human body that contain the genetic information necessary to direct the growth and normal functioning of all cells and systems of the body. A normal individual has a total of 46 chromosomes in each cell, two of which are responsible for determining gender. Normally, females have two X chromosomes, and males have one X and one Y chromosome.

In Turner syndrome, an error occurring very early in development results in an abnormal number and arrangement of chromosomes. Most commonly, an individual with Turner syndrome will be born...