Turner Syndrome

Turner syndrome (TS) is a genetic disorder that occurs in about 1 in 2,500 female babies. Girls with TS are shorter than most females, as they don’t go through normal puberty as they grow into adulthood. Additionally, they may also have other health issues, such as heart or kidney problems. However, the seriousness of these problems varies from female to female and many of the health problems affecting girls and women with Turner syndrome can be managed or fixed with treatment.

When a baby is conceived, a normal egg cell and normal sperm cell start with 46 chromosomes. The egg and sperm cells then divide in half. The egg and sperm cells then have 23 chromosomes each. When a sperm with 23 chromosomes fertilizes an egg with 23 chromosomes, the baby will then have a complete set of 46 chromosomes or 23 pairs. Half are from the father and half are from the mother. The 23rd pair is called the sex chromosomes. In females, the 23rd pair is two X chromosomes. In males, the 23rd pair is one X and one Y chromosome.

About half of all girls with Turner syndrome have a monosomy X disorder. Monosomy means that a person is missing one chromosome in the pair. Instead of 46 chromosomes, the person has only 45 chromosomes. This means a girl with TS has only one X chromosome in her 23rd pair. The missing sex chromosome error can occur in either the mother's egg cell or the father's sperm cell.

Other TS cases have the normal number of 46 chromosomes, but with part of the X chromosome missing. Girls with ‘mosaic’ TS have X-chromosome changes in only some cells, but not all cells. The features of TS depend on which part of the X chromosome is missing.

During a pregnancy, your health care provider may see a structure called a cystic hygroma during a fetal ultrasound. A cystic hygroma is a fluid-filled sac at the base of the neck. It often goes away before birth, but sometimes the sac is there when the baby is born.

About 50 percent of girls born with TS will have puffy hands and feet at birth. They will also have a wide neck with folds of skin down the sides of the neck (called webbing). Girls with TS may also have:

• Feeding problems as a baby
• Short height
• A low hairline at the back of the neck
• Small differences in the shape and position of the ears
• Broad chest with widely spaced nipples
• More small brown moles (nevi) on the skin than normal
• Deep-set nails 
• Small jaw
• Narrow top of the inside of the mouth
• Skeletal problems

Chromosome problems such as TS can often be diagnosed before your child is born. This is done by looking at cells in the amniotic fluid or from the placenta. This can also be done by looking at the amount of the baby’s DNA in the mother's blood, which is a noninvasive prenatal screening. These tests are very accurate.

Fetal ultrasound during pregnancy can also show the possibility of Turner syndrome. But ultrasound is not 100 percent accurate. Problems due to the disorder may not be seen with ultrasound.

If a health care provider thinks that your newborn baby girl may have TS, he or she will usually take a small sample of your baby’s blood. The lab will look at the sample to see if one X sex chromosome or parts of the X-chromosome is missing.

Your health care provider may refer you to a genetic counselor. This expert can explain the results of chromosome tests, as well as tests available to diagnose chromosome problems before a baby is born.

Sometimes a girl with TS doesn’t have any problems as a baby or child. It’s only when she doesn’t go through puberty or is shorter than her peers that her health care provider may suspect TS.

Being shorter than normal is the most common feature of TS as your child grows. The average adult height of a woman with TS is 4 feet, 8 inches. Your child may also have cubitus valgus. This means that when she stands with her arms at her side, her elbows will be slightly bent. She can’t keep her arms perfectly straight at her side.

Most women with TS are born with poorly formed or missing ovaries. Ovaries make estrogen, and without it a girl with TS will not develop sexually. The usual signs of puberty don’t happen unless the girl is given hormone therapy. This includes breast development and menstrual periods. Many girls with the syndrome may not be able to have children as adults.

Other common problems with TS affect the heart, kidney and thyroid. About 1 in 10 girls with TS are born with coarctation of the aorta. This means the main artery that leaves the heart is narrowed. This problem sometimes needs to be fixed with surgery.

Girls with TS generally have normal intelligence and tend to score higher on their verbal IQ than their nonverbal IQ. But they may have problems in the areas of spatial perception. They may also have certain learning disabilities.

Other possible problems include:

• Middle ear infections
• Diabetes
• Dry skin
• High blood pressure

There is no cure for TS. But many of the more serious problems can be treated. For example, growth hormone and androgen therapy can increase the final adult height of a girl. Your child may need hormone therapy to develop secondary sex traits such as breasts and have menstrual periods. Surgery can fix coarctation of the aorta, if needed. And medicines are available to treat high blood pressure, diabetes and thyroid problems. A woman with TS may have children by using donor eggs.

Researchers don’t know how to prevent the chromosome error that causes this disorder. In general, a woman who has a child with Turner syndrome is not at increased risk of having another baby with the condition. TS is usually not inherited in families but happens randomly.

If your baby girl is born with TS, there are things you can do to take care of yourself and your baby:

• Keep all appointments with your baby’s health care provider.
• Talk with your health care provider about other providers (genetics, endocrinology, cardiology, ENT, orthopedics, gynecology, etc.) who will be involved in your child’s care. Your child may receive care from a multidisciplinary team that may include experts such as counselors, social workers, genetic counselors, physical therapists and speech therapists.
• Call your health care provider if you are concerned about your baby’s symptoms.
• Think about having genetic testing and counseling to understand your risk.
• Tell others about your baby’s condition. Work with your child’s health care provider to create a treatment plan.
• Reach out for support from local community services. Being in touch with other parents who have a daughter with TS can also be helpful.