Turner syndrome
What is Turner syndrome?
Turner syndrome is a genetic condition that affects only females. It happens when one of the two X chromosomes is missing or partially missing. X chromosomes are the structures in cells that carry genetic information. Most females have two complete X chromosomes, but girls with Turner syndrome have only one complete X chromosome or have one that is incomplete.
This missing genetic material affects how the body develops before and after birth. Turner syndrome occurs in about 1 in 2,000 to 2,500 live female births. It can affect growth, heart development, and the function of the ovaries. The ovaries are reproductive organs that produce eggs and hormones like estrogen. Because the ovaries may not develop properly, many girls with Turner syndrome have low levels of sex hormones.
The condition is not inherited from parents in most cases. It happens randomly during the formation of reproductive cells or in early fetal development. Early diagnosis and treatment can help girls with Turner syndrome live healthy, fulfilling lives. Many women with this condition go on to have successful careers and relationships with proper medical care and support.
Symptoms
- Short stature and slower growth during childhood
- Webbed neck or a broad chest with widely spaced nipples
- Low hairline at the back of the head
- Swelling of hands and feet, especially in newborns
- Delayed puberty with little breast development
- Absence of menstrual periods
- Heart defects or kidney abnormalities
- Hearing problems or frequent ear infections
- Learning difficulties, especially with spatial concepts and math
- Infertility due to underdeveloped ovaries
Some girls with Turner syndrome have mild symptoms and may not be diagnosed until their teenage years. Others have more obvious physical features that lead to earlier diagnosis. The severity of symptoms varies widely from person to person.
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Causes and risk factors
Turner syndrome is caused by a missing or incomplete X chromosome. This happens randomly and is not caused by anything the parents did before or during pregnancy. Most cases occur when an egg or sperm forms incorrectly, missing one sex chromosome. Sometimes the error happens during early cell division after conception. In some girls, only some cells are missing the X chromosome while others have both X chromosomes. This is called mosaic Turner syndrome and may cause milder symptoms.
Risk factors for Turner syndrome are not well understood because it happens randomly. Maternal age does not appear to increase the risk like it does for some other genetic conditions. The condition affects females of all ethnic backgrounds equally. Girls with Turner syndrome cannot pass the condition to their children because most are unable to conceive naturally due to ovarian dysfunction. However, with assisted reproductive technology, some women with mosaic Turner syndrome or milder forms may be able to become pregnant.
How it's diagnosed
Turner syndrome is diagnosed through genetic testing called a karyotype. This test examines chromosomes in blood cells to look for missing or abnormal X chromosomes. Some cases are detected before birth through prenatal screening or ultrasound findings. After birth, doctors may suspect Turner syndrome based on physical features like short stature or a webbed neck. Blood tests measuring hormone levels can support the diagnosis and help guide treatment.
Hormone testing is an important part of monitoring Turner syndrome. Girls with this condition often have low levels of estradiol and estrone, which are forms of estrogen. They may also have high levels of LH, a hormone that signals the ovaries to produce estrogen. Rite Aid offers hormone testing through Quest Diagnostics labs at over 2,000 locations nationwide. Regular monitoring of these hormone levels helps doctors determine when to start hormone replacement therapy. Early diagnosis and treatment can help improve growth and development outcomes.
Treatment options
- Growth hormone therapy to increase height, usually starting in early childhood
- Estrogen replacement therapy to start puberty and develop secondary sexual characteristics
- Progesterone therapy to establish regular menstrual cycles and protect uterine health
- Regular monitoring of heart health with echocardiograms and blood pressure checks
- Hearing tests and treatment for ear infections or hearing loss
- Kidney function tests and imaging to check for structural abnormalities
- Thyroid function monitoring as autoimmune thyroid conditions are more common
- Bone density screening to prevent osteoporosis
- Educational support for learning differences
- Fertility counseling and assisted reproductive technology for those who wish to have children
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Frequently asked questions
Turner syndrome cannot be cured because it is a genetic condition present from birth. However, treatments can address many of the symptoms and complications. Growth hormone therapy can improve height, and estrogen replacement can support sexual development and bone health. With proper medical care, most women with Turner syndrome live full, healthy lives.
Turner syndrome can be diagnosed at different ages depending on symptoms. Some cases are detected before birth through prenatal testing. Others are diagnosed in infancy due to physical features like swelling or heart defects. Many girls are diagnosed during childhood when short stature becomes apparent or in teenage years when puberty does not start.
Most girls with Turner syndrome do not go through puberty naturally because their ovaries do not function properly. They typically need estrogen replacement therapy to develop breasts, grow pubic hair, and start menstrual periods. Treatment usually begins around age 11 or 12, similar to when puberty would normally start. Early treatment helps with both physical development and emotional well-being.
Most women with Turner syndrome cannot conceive naturally because their ovaries do not produce eggs. However, some women with mosaic Turner syndrome may have some ovarian function and could potentially become pregnant. Others may use donor eggs with in vitro fertilization to carry a pregnancy. Pregnancy in Turner syndrome requires careful medical monitoring due to increased risks.
Hormone blood tests are essential for monitoring Turner syndrome. Tests for estradiol and estrone check estrogen levels, which are usually low in this condition. LH testing measures a hormone that is often elevated when the ovaries are not working properly. These tests help doctors determine when to start hormone therapy and monitor treatment effectiveness.
Turner syndrome is not typically inherited from parents. It occurs randomly during the formation of eggs or sperm or in early fetal development. Parents of a child with Turner syndrome do not have an increased risk of having another child with the condition. Genetic counseling can provide more information about individual family situations.
About 30% of girls with Turner syndrome have heart defects. Common problems include a bicuspid aortic valve, coarctation of the aorta, and aortic dilation. These conditions can be serious and require regular monitoring with echocardiograms. Some heart defects need surgical repair. Blood pressure should be checked regularly throughout life.
Most girls with Turner syndrome have normal intelligence. However, they may have specific learning differences, particularly with spatial reasoning, math, and attention. These challenges can be addressed with educational support and tutoring. Verbal skills are often a strength. Early intervention and appropriate accommodations help girls succeed in school and beyond.
Women with Turner syndrome have an increased risk of osteoporosis, a condition where bones become weak and brittle. This happens partly due to low estrogen levels if not treated with hormone replacement. Adequate calcium and vitamin D intake, weight-bearing exercise, and estrogen therapy help maintain bone density. Regular bone density screening is recommended starting in young adulthood.
With proper medical care, women with Turner syndrome can have a normal or near-normal life expectancy. The main health concerns that can affect longevity are heart problems and high blood pressure. Regular monitoring and treatment of these conditions are essential. Early diagnosis, consistent medical follow-up, and a healthy lifestyle all contribute to better long-term outcomes.