Turner Syndrome

Turner syndrome is a disorder caused by a partially or completely missing X chromosome. This condition affects only females.

Overview

Turner syndrome is a disorder caused by a partially or completely missing X chromosome that affects only females. It can cause infertility and heart problems and alter a female’s appearance.

Most people have 46 chromosomes in each cell — 23 from their mother and 23 from their father. The 23rd pair of chromosomes are called the sex chromosomes — X and Y — because they determine whether a person is male or female. Females have two X chromosomes (XX) in most of their cells, and males have one X chromosome and one Y chromosome (XY) in most of their cells.

Turner syndrome most often occurs when a female has one normal X chromosome, but the other X chromosome is missing (45,X). Other forms of Turner syndrome result when one of the two chromosomes is partially missing or altered in some way.

The condition is much more common among pregnancies that do not survive to term, including miscarriages and stillbirths. Very few pregnancies in which the fetus has Turner syndrome result in live births, as most end in early pregnancy loss.

Turner syndrome is not considered a disability, although it can cause certain learning challenges, particularly with mathematics and memory. With proper medical care, most girls and women with Turner syndrome lead normal, healthy, productive lives.

Related Terms: Turner syndrome is also known as monosomy X, XO syndrome, and 45,X syndrome

Signs and Symptoms

Turner syndrome causes a variety of symptoms in girls and women. For some, symptoms are mild, but for others, Turner syndrome can cause serious health problems. In general, women with Turner syndrome have female sex characteristics, but these characteristics are underdeveloped compared to the typical female.

Turner syndrome can affect many areas of health:

Appearance

Features may include a short neck with a webbed appearance, a low hairline at the back of the neck, low-set ears, hands and feet that are swollen or puffy at birth, and soft nails that turn upward.

Cardiovascular

Turner syndrome can cause problems with the heart or major blood vessels. Some girls with Turner syndrome have a constriction, or narrowing, of the aorta. Many girls with Turner syndrome have an abnormal valve between the heart and the aorta, which usually does not cause symptoms but can lead to infection of the valve or damage to the aorta. Heart defects are the major cause of premature death in women and girls with Turner syndrome. Some women and girls with Turner syndrome also have high blood pressure.

Cognitive

Women and girls with Turner syndrome have normal intelligence. Some, however, have challenges learning mathematics or with visual-spatial coordination, such as determining the relative positions of objects in space. Some girls may also have trouble understanding nonverbal communication — such as body language and facial expression — and interacting with peers.

Diabetes

Women with Turner syndrome are at higher risk for type 2 diabetes.

Eyes

Minor eye problems that can be corrected by glasses may occur.

Gluten intolerance

Some women and girls with Turner syndrome have gluten intolerance, also called celiac disease.

Hearing

Ear malformations and hearing problems are common in women and girls with Turner syndrome. Girls with Turner syndrome may be prone to ear infections, and repeated infections may lead to hearing loss. Some women and girls with Turner syndrome may need hearing aids as children or adults.

Kidneys

Kidney function is usually normal in Turner syndrome, but some women and girls with this condition have kidneys that look abnormal. Many with Turner syndrome have kidney abnormalities, though the only reported effect has been an increased risk for urinary tract infections.

Osteoporosis

Women with Turner syndrome often have low levels of the hormone estrogen, which can put them at risk for osteoporosis. Osteoporosis can cause height loss and bone fractures.

Puberty

Most girls with Turner syndrome do not start puberty naturally. They may not develop breasts or start getting a period.

Reproduction and Pregnancy

In most girls with Turner syndrome, the ovaries are missing or do not function properly. Without the estrogen made by their ovaries, girls with Turner syndrome will not develop breasts. Most women with Turner syndrome cannot become pregnant without assistive technology.

Pregnancy complications present specific risks for women with Turner syndrome. Pregnant women with Turner syndrome are at increased risk for high blood pressure during pregnancy, which can result in complications including preterm birth and fetal growth restriction. Women with Turner syndrome are also at risk for aortic dissection during pregnancy, which happens about 2% of the time. An aortic dissection is a tear in or damage to the inner wall of the aorta — the major artery carrying blood to the heart. Damage to the aorta’s inner wall causes blood to flow rapidly into the lining of the aorta. This can restrict the main flow of blood through the aorta or cause the aorta to balloon into a condition called an aneurysm. An aneurysm can rupture, which can be life-threatening.

Spine

Scoliosis, or deformity of the spine, occurs in 10% of adolescent girls with Turner syndrome.

Stature

Girls with Turner syndrome grow more slowly than other children. Without treatment, they tend to have short statures, around 4 feet, 8 inches, as adults. Girls often have normal height for the first three years of life, but then have a slow growth rate, and at puberty they do not have the usual growth spurt.

Thyroid

Many women and girls with Turner syndrome have thyroid issues. The most common is hypothyroidism, or an underactive thyroid gland. Symptoms of hypothyroidism include decreased energy, intolerance to cold, and dry skin.

Diagnosis

Healthcare providers use a combination of physical symptoms and the results of a genetic blood test, called a karyotype, to determine the chromosomal characteristics of the cells in a female’s body. The test shows if one of the X chromosomes is partially or completely missing.

Diagnosis can happen at different life stages:

  • During pregnancy: Turner syndrome can be diagnosed during pregnancy by testing the cells in the amniotic fluid. It may also be suspected during an ultrasound test and confirmed by prenatal testing (chorionic villous sampling or amniocentesis) to obtain cells from the unborn baby for chromosomal analysis. If a diagnosis is confirmed prenatally, the baby may be under the care of a specialist pediatrician immediately after birth.
  • At birth: Newborns may be diagnosed after heart problems are detected or after certain physical features (such as swollen hands and feet or webbed skin on the neck) are noticed. Other characteristics, like widely spaced nipples or low-set ears, may also lead to a suspicion of Turner syndrome.
  • During childhood: Many girls are diagnosed in early childhood when a slow growth rate and other features are identified.
  • During adolescence: Some girls may be diagnosed as teenagers because of a slow growth rate or a lack of puberty-related changes.
  • During adulthood: Still others may be diagnosed as adults when they have difficulty becoming pregnant.

The two main clinical features that prompt diagnosis are short stature and the lack of development of the ovaries.

Causes and Risk Factors

Turner syndrome occurs when part or all of an X chromosome is missing from most or all of the cells in a girl’s body. A girl normally receives one X chromosome from each parent. The error that leads to the missing chromosome appears to happen during the formation of the egg or sperm.

Most commonly, a girl with Turner syndrome has only one X chromosome. Occasionally, she may have a partial second X chromosome. Because she is missing part or all of a chromosome, certain genes are missing. The loss of these genes leads to the symptoms of Turner syndrome.

Sometimes, girls with Turner syndrome have some cells that are missing one X chromosome (45,X) and some that are normal. This condition is called mosaicism. If the second sex chromosome is lost from most of a girl’s cells, it is likely that she will have symptoms of Turner syndrome. If the chromosome is missing from only some of her cells, she may have no symptoms or only mild symptoms.

Researchers have identified one gene called SHOX that is important for bone development and growth. Missing one copy of this gene likely causes short stature and skeletal abnormalities in women with Turner syndrome. Researchers have not yet determined which other genes on the X chromosome are responsible for most signs and symptoms of Turner syndrome.

Turner syndrome is usually not inherited, but it is genetic. It is caused by a random error that leads to a missing X chromosome in the sperm or egg of a parent. Generally, Turner syndrome is not passed on from mother to child because, in many cases, women with Turner syndrome have infertility.

Treatment and Management

Although there is no cure for Turner syndrome, some treatments can help minimize its symptoms. Girls and women with Turner syndrome usually require care from a variety of specialists throughout their lives.

Regular health checks and access to a wide variety of specialists are important to care for the various health problems that can result from Turner syndrome, including ear infections, high blood pressure, and thyroid problems.

Key Treatments Include:

  • Human growth hormone: If given in early childhood, hormone injections can often increase adult height by a few inches. Injections often begin in early childhood.
  • Estrogen replacement therapy (ERT): ERT can help start the secondary sexual development that normally begins at puberty, around age 12. This includes breast development and the development of wider hips. Healthcare providers may prescribe a combination of estrogen and progesterone to girls who haven’t started menstruating by age 15. ERT also provides protection against bone loss. Estrogen is also given to prevent osteoporosis.
  • Heart surgery: Babies born with a heart murmur or narrowing of the aorta may need surgery to correct the problem. A cardiologist will assess and follow up any treatment necessary.
  • Blood pressure management: High blood pressure is quite common in women with Turner syndrome. Blood pressure should be checked routinely and, if necessary, treated with medicine.
  • Thyroid treatment: Thyroid function should be monitored during routine health maintenance visits and treated if necessary. Hypothyroidism is easily treated with medicine.
  • Ear and hearing care: An ear, nose, and throat (ENT) specialist may be involved in caring for this health issue.
  • Fertility assistance: Almost all women with Turner syndrome are infertile, but pregnancy with donor embryos may be possible. In one study, as many as 40% of women with Turner syndrome got pregnant using donated eggs.

During childhood and adolescence, girls may be under the care of a pediatric endocrinologist, who is a specialist in childhood conditions of the hormones and metabolism. Special clinics for the care of girls and women with Turner syndrome are available in some areas, with access to a variety of specialists. Early preventive care and treatment is very important.

Living With Turner Syndrome

Having appropriate medical treatment and support allows a woman with Turner syndrome to lead a normal, healthy, and happy life.

If you or your daughter has been diagnosed with Turner syndrome, you may wonder what to expect as she grows up. The following addresses some common questions:

Will women with Turner syndrome:

  • Mature normally? Most girls with Turner syndrome do not mature typically. They may not develop breasts or start getting a period. Estrogen treatment can replace hormones that the body doesn’t naturally produce, spurring development and preventing osteoporosis.
  • Have problems in school? Some girls with Turner syndrome have difficulty with arithmetic, visual memory, and visio-spatial skills. They may also have some trouble understanding nonverbal communication and interacting with peers.
  • Need extra healthcare as they grow up? Girls and women with Turner syndrome usually require care from a variety of specialists throughout their lives.
  • Have a normal sex life as an adult? Women with Turner syndrome can enjoy normal sex lives. Even though many women with Turner syndrome have non-functioning ovaries and are infertile, their vagina and womb are totally normal.
  • Be able to have children? Most women with Turner syndrome cannot get pregnant naturally. Those who can are at risk for blood pressure-related complications, which can lead to premature birth or fetal growth restriction. Pregnancy is also associated with increased risk for maternal complications, including aortic dissection and rupture.

Find Clinical Trials

Clinical trials uncover better ways to prevent, diagnose, treat, and understand diseases and conditions. To ensure results apply to everyone, volunteers of all ages, sexes, and backgrounds, including both healthy individuals and those with specific medical conditions, are needed. Find clinical trials on Turner Syndrome.

Community Support

The following organizations offer support and information for people with Turner syndrome and their families:

Note: This resource list is for informational purposes only. It is not comprehensive, and an organization’s inclusion does not constitute an endorsement by NIH. 

Research Information

The National Institutes of Health (NIH) is the largest public funder of biomedical research in the world. NIH invests most of its budget in medical research seeking to enhance life and to reduce illness and disability. NIH-funded research has led to breakthroughs and new treatments helping people live longer, healthier lives, and building the research foundation that drives discovery.

NIH is at the forefront of research on Turner syndrome and its effects on women’s reproductive, cardiovascular, and psychosocial health. A main focus of research being conducted by NIH researchers is the cardiovascular effects of Turner syndrome in women.

Active research topics include:

  • Characteristics that put women at high risk for aortic dissection
  • Comparing the effectiveness of drugs to prevent dilation of the aorta
  • Psychosocial functioning, including shyness and social anxiety
  • The impact of infertility, childlessness, sex-steroid effects, and altered body image on social functioning
  • Hormonal and genetic aspects of gender-based differences in immunological, metabolic, and cognitive function
  • The impact of Turner syndrome on neurodevelopment and neural function
  • Development of a new, low-cost newborn screening test for Turner syndrome to decrease the number of girls who are not diagnosed until age 10 or later
  • Effects on cardiac function and insulin resistance as well as the long-term effects of therapies such as estrogen and growth hormone

Find NIH-funded research projects using NIH RePORTER, a searchable database of current and past research projects supported by NIH and other federal agencies