A small percentage of females with Turner syndrome retain normal ovarian function through young adulthood. About 30 percent of females with Turner syndrome have extra folds of skin on the neck webbed neck , a low hairline at the back of the neck , puffiness or swelling lymphedema of the hands and feet, skeletal abnormalities, or kidney problems.
One third to one half of individuals with Turner syndrome are born with a heart defect, such as a narrowing of the large artery leaving the heart coarctation of the aorta or abnormalities of the valve that connects the aorta with the heart the aortic valve.
Complications associated with these heart defects can be life-threatening. Most girls and women with Turner syndrome have normal intelligence. Developmental delays, nonverbal learning disabilities, and behavioral problems are possible, although these characteristics vary among affected individuals.
This condition occurs in about 1 in 2, newborn girls worldwide, but it is much more common among pregnancies that do not survive to term miscarriages and stillbirths. Turner syndrome is related to the X chromosome , which is one of the two sex chromosomes. People typically have two sex chromosomes in each cell: females have two X chromosomes, while males have one X chromosome and one Y chromosome. Turner syndrome results when one normal X chromosome is present in a female's cells and the other sex chromosome is missing or structurally altered.
The missing genetic material affects development before and after birth. About half of individuals with Turner syndrome have monosomy X , which means each cell in the individual's body has only one copy of the X chromosome instead of the usual two sex chromosomes. Turner syndrome can also occur if one of the sex chromosomes is partially missing or rearranged rather than completely absent.
Some women with Turner syndrome have a chromosomal change in only some of their cells, which is known as mosaicism. Women with Turner syndrome caused by X chromosome mosaicism are said to have mosaic Turner syndrome. Researchers have not determined which genes on the X chromosome are associated with most of the features of Turner syndrome.
They have, however, identified one gene called SHOX that is important for bone development and growth. The loss of one copy of this gene likely causes short stature and skeletal abnormalities in women with Turner syndrome. Most cases of Turner syndrome are not inherited. When this condition results from monosomy X , the chromosomal abnormality occurs as a random event during the formation of reproductive cells eggs and sperm in the affected person's parent.
An error in cell division called nondisjunction can result in reproductive cells with an abnormal number of chromosomes. For example, an egg or sperm cell may lose a sex chromosome as a result of nondisjunction.
If one of these atypical reproductive cells contributes to the genetic makeup of a child, the child will have a single X chromosome in each cell and will be missing the other sex chromosome. Often, their signs and symptoms are milder than those of other girls with the X condition. The condition is named for Dr. Henry Turner, an endocrinologist, who in noted a set of common physical features in some of his female patients. Most girls with Turner syndrome who don't get treatment are shorter than their peers, with an average final adult height of 4 feet 7 inches.
Girls who have Turner syndrome don't have typical ovarian development. Because the ovaries are responsible for making the hormones that control breast growth and menstruation, most girls with TS won't go through all the changes associated with puberty unless they get treatment for the condition.
Nearly all girls will be infertile, or unable to become pregnant on their own. Other health problems that may happen with TS include kidney problems, heart problems, high blood pressure , obesity , diabetes mellitus, vision problems, thyroid problems, and abnormal bone development.
Some girls with TS may have learning problems, particularly in math. Many also struggle with tasks requiring spatial skills, such as map reading or visual organization. Some girls also have problems with body image or self-esteem. Girls with Turner syndrome are usually diagnosed either at birth or around the time they might be expected to go through puberty.
If a baby girl has some of the signs of Turner syndrome, a doctor will usually order a special blood test called a karyotype pronounced: CARE-ee-oh-tipe. The test counts the number of chromosomes and can identify any that are abnormally shaped or have missing pieces.
In some cases, there are no clear signs that a girl has the condition until she reaches the age at which she would normally go through puberty. To diagnose Turner syndrome, doctors use a special blood test that looks at chromosomes, called a karyotype. If the karyotype blood test shows that a girl has Turner syndrome, her doctor may order more tests to check for problems with the kidneys, heart, hearing, and other problems that are often associated with Turner syndrome. Because TS is a chromosomal disorder, there's no cure for the condition.
But a number of treatments can help:. Girls with Turner syndrome may have some kinds of learning problems. But most can attend regular school and classes, and usually:. If you have Turner syndrome, you know that it can affect you in several ways. But it's only a small part of your total physical, emotional, and intellectual self. A girl with Turner syndrome only has 1 normal X sex chromosome, rather than the usual 2.
This chromosome variation happens randomly when the baby is conceived in the womb. It is not linked to the mother's age. Read more about the genetic cause of Turner syndrome. Females with Turner syndrome often have a wide range of symptoms and some distinctive characteristics.
Almost all girls with Turner syndrome:. As height and sexual development are the 2 main things affected, Turner syndrome may not be diagnosed until a girl fails to show sexual development associated with puberty , usually between the ages of 8 and 14 years.
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