Turner syndrome

Definition

Turner syndrome is a rare genetic condition in which a female does not have the usual pair of X chromosomes.

Alternative Names

Bonnevie-Ullrich syndrome; Gonadal dysgenesis; Monosomy X; XO

Causes

The typical number of human chromosomes is 46. Chromosomes contain all of your genes and DNA, the building blocks of the body. Two of these chromosomes, the sex chromosomes, determine if you become a boy or a girl.

In Turner syndrome, cells are missing all or part of an X chromosome. The condition only occurs in females. Most commonly, a female with Turner syndrome has only 1 X chromosome. Others may have 2 X chromosomes, but one of them is incomplete. Sometimes, a female has some cells with 2 X chromosomes, but other cells have only 1. This situation is called mosaicism.

Symptoms

Possible findings of the head and neck include:

Other findings may include:

A child with Turner syndrome is much shorter than children who are the same age and sex. This is called short stature. This problem may not be noticed in girls before age 11.

Puberty may be absent or not complete. If puberty occurs, it most often begins at the normal age. After the age of puberty, unless treated with female hormones, these findings may be present:

Sometimes, the diagnosis of Turner syndrome may not be made until adulthood. It may be discovered because a woman has very light or no menstrual periods and problems becoming pregnant.

Exams and Tests

Turner syndrome can be diagnosed at any stage of life.

It may be diagnosed before birth if:

The health care provider will perform a physical exam and look for signs of atypical development. Infants with Turner syndrome often have swollen hands and feet.

The following tests may be performed:

Other tests that may be done periodically include:

Treatment

Growth hormone may help a child with Turner syndrome grow taller.

Estrogen and other hormones are often started when the girl is 12 or 13 years old.

Women with Turner syndrome who wish to become pregnant may consider using a donor egg.

Women with Turner syndrome may need care or monitoring for the following health problems:

Other issues may include:

Outlook (Prognosis)

Those with Turner syndrome can have a normal life when carefully monitored by their provider.

Possible Complications

Other health problems may include:

Prevention

There is no known way to prevent Turner syndrome.

References

Bacino CA, Lee B. Cytogenetics In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 98.

Styne DM. Physiology and disorders of puberty. In: Melmed S, Auchus RJ, Goldfine AB, Koenig RJ, Rosen CJ, eds. Williams Textbook of Endocrinology. 14th ed. Philadelphia, PA: Elsevier; 2020:chap 26.

Thompson S, Wherrett DK. Disorders of sex development. In: Martin RJ, Fanaroff AA, eds. Fanaroff and Martin's Neonatal-Perinatal Medicine. 12th ed. Philadelphia, PA: Elsevier; 2025:chap 93.



Review Date: 12/31/2023
Reviewed By: Anna C. Edens Hurst, MD, MS, Associate Professor in Medical Genetics, The University of Alabama at Birmingham, Birmingham, AL. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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