Turner Syndrome

Humans have 23 pairs of chromosomes, 46 single chromosomes in total. (Read about "Genetics") Most of us have one pair of sex chromosomes. Males have an X and a Y chromosome, and females have two X chromosomes. Turner syndrome (TS) occurs in females when one of her X chromosomes is damaged or missing, says the National Institutes of Health (NIH).

NIH says about half of females with TS have a type called "Monosomy X." This means each cell in her body only has one X chromosome rather than two. This missing genetic information is what causes the many conditions that TS females develop. A second type of TS occurs when changes in chromosomes happen in only some of the female's cells. This type is called "Mosaicism," because the chromosome changes have a mosaic pattern.

Dr. Henry Turner, whom the syndrome is named after, was one of the first people to describe TS in the 1930's. About one in every 2,000 female babies born are affected by this birth defect (Read about "Birth Defects") and to date, no one understands exactly why this happens. Scientists believe TS mostly happens by chance, during the time eggs or sperm are developing during reproduction, according to NIH, which also says it is not generally inherited in families.

Females who have TS are unusually short, with adult height averaging only about 4' 8". According to the Turner Syndrome Society (TSS), they can have other noticeable features such as:

• droopy eyes
• lazy eyes (Read about "Amblyopia")
• extra skin around the neck (webbed neck)
• a low hairline, hair closer to the shoulders
• low set ears
• broad chest
• a curving spine or scoliosis (Read about "Curvature of the Spine")

According to TSS, females with TS can have several challenging medical issues throughout their lives. In addition to slow growth, other problems can include:

• otitis media (Read about "Otitis Media")
• thyroid issues (Read about "Thyroid")
• kidney abnormalities (Read about "Kidney Disease")
• hearing loss (Read about "The Ear & Hearing")
• heart complications (Read about "The Heart & Cardiovascular System")

A major medical problem for most TS individuals is ovarian failure. (Read about "The Ovaries") As a result, there is a hormone deficiency. That generally means a delay of puberty, which must often be started with hormonal treatments. It also means infertility (Read about "Infertility"), because the ovaries cannot produce eggs. This also usually means a lack of menstrual cycles. (Read about "Menstrual Disorders")

The good news is that scientists say intelligence levels are the same for people with TS as it is for people without the syndrome. However, behavior problems, learning disabilities, memory, and attention issues can occur, resulting in problems with math comprehension, sense of direction, and social skills says TSS. Researchers are looking for solutions to these problems.

Diagnosis & treatment

According to TSS, Turner syndrome is diagnosed by a test called the karyotype test, which can be performed before or after a baby girl is born. (Read about "Laboratory Testing") A trained specialist or geneticist looks at the chromosomes in the cells and searches for abnormalities such as missing all or part of one of the sex chromosomes.

Turner syndrome can be diagnosed at any stage in a female's life, but according to NIH, is usually evident by age 5. TSS says that it is important to remember that no matter what age it is discovered that a female has TS, her heart and kidneys should be tested for abnormalities.

Since the ovaries in TS females do not function properly, hormone therapy is often started in young girls, 12-14 years of age. Estrogen is given in small doses to help start the onset of puberty and breast development. The hormone is given in higher doses and progesterone can be added in order to initiate a monthly menstrual cycle, says TSS.

TSS says about 90 percent of women with the syndrome have early ovarian failure. This means it is not possible to have children through natural methods because their ovaries do not work properly. A high-risk obstetrician should follow the pregnancy of women with TS, according to the March of Dimes. (Read about "Healthy Pregnancy")

Women with TS have options when it comes to growing their families; many adopt children, some develop close relationships with nieces, nephews, friends and neighbors. Some women with TS, as other women in the United States, are happy without having children according to TSS.

Scientists are making successful discoveries in their TS research. They found one gene called "SHOX," which is the main cause of the short stature in TS females. The Food and Drug Administration (FDA) has approved treatments with human growth hormone (hGH) which helps TS women reach a more normal adult height. Use of this therapy, says TSS, should be considered when a TS female experiences growth failure and/or drops below the 5th percentile of the normal female growth curve. Promising findings such as these may lead to better treatments for other TS features in the future says NIH.

If you have TS, consult your healthcare provider for individualized treatments plans. Physicians, family and patients should decide on treatment options together. Building a strong relationship with the right healthcare team and the support of loved ones can enable females with TS to live happy, healthy lives.