Turner syndrome is a chromosomal disorder in which a female is born with only one X chromosome. It is a female-only genetic disorder that affects about 1 in every 2,000 baby girls. 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.
Turner syndrome (TS) is the result of a chromosomal abnormality. Girls who have this condition usually are shorter than average and infertile due to early loss of ovarian function. Usually, a person has 46 chromosomes in each cell, divided into 23 pairs, which includes two sex chromosomes. Half of the chromosomes are inherited from the father and the other half from the mother. A chromosome contains genes, which determine an individual's characteristics, such as eye color and height. Girls typically have two X chromosomes (or XX), but girls with Turner syndrome have only one X chromosome or are missing part of one X chromosome.
Turner syndrome is not caused by anything the parents did or did not do. The disorder is a random error in cell division that happens when a parent's reproductive cells are being formed. Girls born with the X condition in only some of their cells have mosaic Turner syndrome. Often, their signs and symptoms are milder than those of other girls with the non-mosaic condition.
What Problems does Turner Syndrome have?
Girls who have Turner syndrome don't have typical ovarian development. They usually don't develop all the secondary sexual characteristics (the physical changes that usually happen in puberty) and are infertile (can't become pregnant) as adults. However, advances in medical technology, including hormonal therapy and in vitro fertilization, can help women with this condition.
Other health problems that may happen with TS include kidney and heart problems, high blood pressure, obesity, diabetes mellitus, thyroid problems, ear infections with decreased hearing, and altered bone development.
Girls with Turner syndrome usually have normal intelligence, but some may have learning problems, particularly in math. Many also struggle with tasks requiring spatial skills, such as map reading or visual organization. Hearing problems are more common in girls with TS.
They aren't at increased risk for major psychological problems, but some girls do have problems with body image or self-esteem and some also might have ADHD.
Despite these physical differences and other problems, with the right medical care, early intervention, and ongoing support, a girl with Turner syndrome can lead a normal, healthy, and productive life.
Signs & Symptoms of Turner Syndrome
Most girls with Turner syndrome are shorter than their peers, with an average final adult height of 4 feet 7 inches, and may have other related physical features.
- "Webbing" of the skin of the neck (extra folds of skin extending from the tops of the shoulders to the sides of the neck)
- A low hairline at the back of the head
- Low-set ears
- Unusual eye features, including drooping of the eyelids
- Altered bone development, especially the bones of the hands and elbows
- A lack of breast development at the expected age (usually by age 13)
- Irregular periods or no periods (amenorrhea)
- A larger than usual number of moles on the skin
How Is Turner Syndrome Treated?
Because TS is a chromosomal disorder, there's no cure for the condition. But a number of treatments can help:
- Growth hormone, either alone or with other hormone treatment, may improve growth and will usually increase final adult height — often into the normal range if treatment is started early enough. The U.S. Food and Drug Administration (FDA) has approved growth hormone for the treatment of Turner syndrome, and most insurance plans now cover this special treatment.
- Estrogen replacement therapy often begins when a girl is 12 or 13 years old to stimulate the development of secondary sexual characteristics (breast development and menstrual periods). This therapy will not reverse infertility, however.
- Cardiac surgery may be necessary to correct specific heart defects.
- Reproductive technologies can help women with Turner syndrome become pregnant. Fertilized donor eggs are used to create embryos, which can be inserted into the uterus of a woman with TS. With the help of hormone treatment, the woman can carry a developing fetus to term.
It's important to assess a girl's intellectual, learning, motor skills, and social maturity before kindergarten. If learning problems are found, early preventive and intervention strategies can help.
