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Turner syndrome

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Illustrations

Pectus excavatum
Pectus excavatum

Alternative names    Return to top

Bonnevie-Ullrich syndrome; Gonadal dysgenesis; Monosomy X

Definition    Return to top

Turner syndrome is a genetic condition that occurs only in females. Female cells normally have two X chromosomes. In Turner syndrome, the girl's cells are missing an X chromosome, or part of an X chromosome. There are a variety of signs and symptoms that can result, but the most common are short height, lack of developing ovaries, and infertility.

Causes, incidence, and risk factors    Return to top

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.

Turner syndrome occurs in about 1 out of 2,000 live births.

Symptoms    Return to top

Possible symptoms include a combination of:

Signs and tests    Return to top

Turner syndrome can be diagnosed at birth or during childhood, puberty, or adulthood. It can be diagnosed before birth if a karyotype is performed as part of prenatal testing.

During a physical examination, the doctor will look for signs of underdeveloped breasts and genitalia, webbed neck, short stature, low hairline in back, simian crease (a single crease in the palm), and abnormal bone development of the chest.

Infants with Turner syndrome often have swollen hands and feet. This is probably from changes in the drainage of the lymphatic system.

The following tests may be performed:

Turner syndrome may also alter the results of the following tests:

Treatment    Return to top

Support Groups    Return to top

For additional information and resources, see www.turnersyndrome.org.

Expectations (prognosis)    Return to top

Those with Turner syndrome can have a normal lifespan and productive life when carefully monitored by their physician.

Complications    Return to top

Prevention    Return to top

There is no known way to prevent Turner syndrome.

Update Date: 10/27/2004

Updated by: Celeste Krauss, M.D., Board Certified Clinical Genetics, Clinical Cytogenetics, Pediatrics and a Founding Fellow, of the American College of Medical Genetics. Review provided by VeriMed Healthcare Network

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