Turner syndrome (TS) is a genetic condition that only affects females. The condition is caused by an abnormal chromasome, and it affects about one in every 2,500 baby girls.
TS was named after Dr Henry Turner, who discovered the condition in 1938.
The condition can cause a range of disabilities, which can be:
- physical,
- emotional, and
- educational.
Missing chromosome
TS occurs when one of the two X chromosomes that are found in females is completely or partially missing.
Chromosomes are strands of deoxyribonucleic acid (DNA) that are found in all of the cells in the human body. They contain instructions that determine a person’s physical and behavioural characteristics. See the Causes section, above, for more details.
Types of Turner syndrome
Cases of TS where an X chromosome is completely missing are sometimes referred to as 'classical' Turner syndrome. ‘Mosaic’ Turner syndrome is where abnormalities only occur in the X chromosome of some of the body’s cells. In such cases, there may be few or no symptoms.
What are the characteristics of Turner syndrome?
Girls and women who have TS often have a wide range of different medical symptoms, or characteristics. However, there are two characteristics that occur in almost all cases of TS. They are:
- being shorter than average in height, and
- a lack of development of the ovaries, leading to infertility.
As stature and sexual development are the two main characteristics of TS, the condition may go undiagnosed until a girl reaches school age or puberty.
The other characteristics of TS vary greatly (see Symptoms, above, for more details). Occasionally, the condition can cause heart, kidney and thyroid problems, bone disorders, and hearing and ear problems.
Girls and women with TS will need regular health checks and treatment throughout their lives. However, most are able to lead relatively normal, healthy lives.
TS is similar to Noonan syndrome, a genetic condition which, like TS, causes a wide range of physical symptoms and distinctive chararacteristics.
See Useful links for information about Noonan syndrome.
