Monosomy X

What is Monosomy X (Turner syndrome)?

Monosomy X, also known as Turner syndrome, is a condition that causes short stature, abnormal puberty, birth defects, and infertility in affected females. It is caused by a difference in the number of sex chromosomes. Females typically have two X chromosomes, while males typically have one X and one Y chromosome. Turner syndrome occurs when a female has only one complete and functioning copy of the X chromosome in the cells of the body instead of two. The symptoms seen in Turner syndrome are a result of this missing material impacting the growth and development of an affected individual.

Common features of Turner syndrome include short stature, puberty that is absent or delayed, infertility, heart and kidney abnormalities, hearing loss, eye and skeletal abnormalities, and thyroid disease. Individuals may have unique physical characteristics such as distinct facial features and a wide and short neck. Most people with Turner syndrome have normal intelligence, though they may experience difficulties in certain areas such as math, memory, attention, or social skills.

How common is Turner Syndrome?

The incidence of Turner syndrome in the population is 1 in 2,500 live births.

How is Turner Syndrome treated?

There is no cure for Turner syndrome. Treatment for the condition is directed at managing the specific symptoms an individual has. Common interventions include medications to help achieve puberty at an appropriate age and increase adult height. Certain birth defects, such as heart defects, may require surgery. For many individuals, assistive reproductive technology may be able to help with fertility.

What is the prognosis for an individual with Turner Syndrome?

With appropriate medical care, many individuals with Turner syndrome have essentially normal lifespans.

Other names for
Monosomy X

Turner syndrome

References

Gravholt et al., 2017, Eur J Endocrinol, 177(3):G1-G70, PMID: 28705803
Gravholt et al., 2019, Nat Rev Endocrinol, 15(10):601-614, PMID: 31213699
Kikkeri et al., 2022, In: StatPearls [Internet], PMID: 32119508
Oktay et al., 2016, J Pediatr Adolesc Gynecol, 29(5):409-416, PMID: 26485320

Resources

Turner Syndrome Society of the United States

Turner Syndrome Society of the United States provides health-related resources to patients, families and physicians for the diagnosis and treatment of Turner syndrome.

Address: 11250 West Road, Suite G, Houston TX 77065

Phone:
1-800-365-9944

Lettercase

The “Understanding a Turner syndrome Diagnosis” booklet is intended for patients whose pregnancy has an increased chance for a prenatal diagnosis of Turner syndrome. This book includes information about Turner syndrome, such as potential medical conditions, available supports, reproductive options, and other resources.

Address: 114 Mineral Industries Building, University of Kentucky, Lexington, KY 40506

Phone:
770-310-3885

Turner Syndrome Foundation

The goal of the Turner Syndrome Foundation (TSF) is to support research initiatives and facilitate education programs that increase professional awareness and enhance medical care of those affected by Turner syndrome. TSF is a registered 501(c)(3) nonprofit organization.

Address: P. O. Box 726 Holmdel, NJ, 07733

Phone:
800-594-4585