In this Article

• What is Turner syndrome?
• What are the symptoms of Turner syndrome?
• How is Turner syndrome diagnosed?
• What is the treatment for Turner syndrome?
• Is Turner syndrome inherited?
• Turner Syndrome Glossary
• Turner Syndrome Index

Is Turner syndrome inherited?

Turner syndrome is not usually inherited in families. Turner syndrome occurs when one of the two X chromosomes normally found in women is missing or incomplete. Although the exact cause of Turner syndrome is not known, it appears to occur as a result of a random error during the formation of either the eggs or sperm.

Humans have 46 chromosomes, which contain all of a person's genes and DNA. Two of these chromosomes, the sex chromosomes, determine a person's gender. Both of the sex chromosomes in females are called X chromosomes. (This is written as XX.) Males have an X and a Y chromosome (written as XY). The two sex chromosomes help a person develop fertility and the sexual characteristics of their gender.

In Turner syndrome, the girl does not have the usual pair of two complete X chromosomes. The most common scenario is that the girl has only one X chromosome in her cells. Some girls with Turner syndrome do have two X chromosomes, but one of the X chromosomes is incomplete. In another scenario, the girl has some cells in her body with two X chromosomes, but other cells have only one. This is called mosaicism.

SOURCE: National Human Genome Research Institute, National Institutes of Health