Turner syndrome is a genetic disorder that causes girls to be short, and prevents them from maturing sexually as they grow into adulthood.
Overall, Turner syndrome occurs in about one out of 2,500 female births.
The occurrence of Turner syndrome is not associated with the mother’s age at the time of pregnancy or birth.
About one-third of girls with Turner syndrome are diagnosed as newborns, another third during childhood and the remaining third during their late teens.
How are chromosomes involved in the onset of Turner syndrome?
Normally, a baby has a complete set of 46 chromosomes in each cell of the body—23 from the father and 23 from the mother.
In some cases, however, one member of a pair of chromosomes is missing, resulting in a total of 45 chromosomes instead of 46—for example, a baby that is born with only one X sex chromosome in each cell, rather than the usual pair (either XX or XY sex chromosomes).
In such a case, the baby is said to have "monosomy X." Monosomy X, or XO, is the karyotype () most frequently seen in Turner syndrome.
How serious a disease is Turner syndrome?
The severity of symptoms varies from patient to patient. For many girls, their Turner syndrome can be managed or corrected with treatment options ranging from growth hormone therapy, estrogen therapy and progesterone therapy to certain medications.
While Turner syndrome is a complicated condition that requires constant medical oversight, most girls with the disease go on to lead normal, happy lives with proper care.
What causes Turner syndrome?
Turner syndrome is caused by a missing or incomplete X chromosome in your child’s genetic makeup.
This may take one of three forms:
- your child is missing an entire X chromosome (most common)
- your child has two X chromosomes, but one is incomplete
- your child has some cells with two X chromosomes, and others with only one
When only part of a chromosome is missing, girls with Turner syndrome usually have milder features of the syndrome. The symptoms expressed will depend on which parts of the chromosome are missing.
What causes a missing chromosome?
Sometimes an error occurs when an egg or sperm cell is forming, causing it to have no sex chromosome (X or Y). When this cell combines with a sperm or egg at fertilization, the resulting cell has only one X chromosome.
While this could happen to either the egg cell or the sperm cell, it usually happens to the sperm cell. There is no known action that either a mother or father could have taken—or not taken—that would have caused, or prevented, the missing sex chromosome.
Signs and symptoms
What are the symptoms of Turner syndrome?
Since Turner syndrome can be diagnosed at different stages in a girl’s life, your daughter’s symptoms may vary depending on her age at diagnosis.
Symptoms detected in the womb/at birth
While performing a fetal ultrasound during a mother’s pregnancy, a physician may see a structure called a cystic hygroma. Cystic hygromas are fluid-filled sacs at the base of the baby’s neck that can indicate the presence of Turner syndrome. Most often, they go away before a baby is born, but in some cases, they’re still present in newborns.
Turner syndrome may also be identified when a woman has an amniocentesis during pregnancy and a karyotype is performed on the fetal cells in the amniotic fluid.
About half of girls born with Turner syndrome have puffy hands and feet at birth, in addition to wideness and “webbing” of the neck.?
Symptoms developing in childhood
A visibly short stature is the most obvious feature of Turner syndrome during a girl’s childhood. Most often, your doctor will notice a decrease in your daughter’s growth percentiles when she’s between 4 and 6 years old.
A girl with Turner syndrome may also have:
- low hairline at the back of her neck
- minor differences in the shape and position of her ears
- a broad chest with widely spaced nipples
- an increased number of small brown moles (called nevi) on her skin
Symptoms developing in late teens
Most girls with Turner syndrome are born with poorly formed or missing ovaries, which can result in infertility. Ovaries produce the hormone estrogen, and without it, incomplete sexual development occurs.
This may result in the following symptoms:
- sparse pubic hair
- incomplete breast development
- inability to menstruate
- vaginal dryness
Infertility caused by missing or poorly formed ovaries is not usually correctible, but hormone therapy can help significantly with other issues affecting your daughter’s sexual development.
Other characteristics of Turner syndrome can include:
- feeding problems during infancy
- heart, kidney and thyroid problems
- coarctation of the aorta (the constriction of the main artery leaving the heart), which sometimes needs to be corrected surgically
- skeletal problems
- cubitis valgus, a condition in which a person standing with their arms at their sides will have their elbows slightly bent
Questions to ask your doctor
- What tests are involved in diagnosing Turner syndrome?
- Will my daughter be screened for other medical problems that may be associated with the condition?
- What’s the best course of treatment, and are there any risks involved?
- What are the long-term effects of the condition?
- What are my daughter’s chances for conceiving children as she moves into adulthood?
Q: What causes a missing chromosome? As a parent, did I do something wrong?
A: Sometimes an error occurs when an egg or sperm cell is forming, causing it to have no sex chromosome (X or Y). When this cell combines with a sperm or egg at fertilization, the resulting cell has only one X chromosome.
While this could happen to either the egg cell or the sperm cell, it usually happens to the sperm cell. There is nothing known that either a mother or father could have done (or not done) that would have caused or prevented this from happening.
Q: Is there a cure for Turner syndrome?
A: There is no cure for Turner syndrome, but many of the more serious problems associated with it can be treated through growth hormone therapy, estrogen therapy, progesterone therapy and other medications. Counseling can also help a girl with Turner syndrome deal with some of the more sensitive issues associated with this condition.
Q: Does Turner syndrome affect mental development?
A: Girls with Turner syndrome have normal intelligence and tend to have higher verbal IQs than nonverbal IQs. They may also have some problems in the areas of spatial perception, non-verbal memory and attention.
Q: Will my daughter be able to have children?
A: Most girls with Turner syndrome are born with poorly formed or absent ovaries, which can result in infertility. Ovaries produce estrogen, and without it, incomplete sexual development occurs.
Infertility caused by missing or poorly formed ovaries is not usually correctible, but hormone therapy can help significantly with other issues related to sexual development. As your daughter moves into adulthood, she may choose to pursue in vetro fertilization or adoption if she wants to have children.
Q: What is the risk of parents who gave birth to a daughter with Turner syndrome having another daughter with Turner syndrome?
A: There is no known risk of recurrence. The chance of having another baby with Turner syndrome has no relationship to the mother’s age.
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