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Turner Syndrome Glossary

Terms to Know about this Growth Disorder

Estrogen is the primary female sex hormone released by the ovaries. Estrogen is essential to the healthy development of female sex characteristics during puberty. Normal ovarian function is required for fertility. Early ovarian insufficiency is common in Turner syndrome (TS), which directly impacts healthy estrogen production and fertility.

Estrogen replacement therapy
The purpose of estrogen replacement therapy is two-fold—to prompt the body into beginning puberty and to maintain healthy sexual development and function throughout adulthood. Estrogen replacement therapy is typically taken by pill or by patch—depending on the specific type of estrogen replacement therapy you are prescribed. Once a girl or woman begins estrogen replacement therapy for Turner syndrome, she'll continue it until she reaches menopause.

Fertility treatments
Fertility treatments increase a woman's chances of conceiving. It is rare for a woman with Turner syndrome to have a child naturally, and fertility treatments—such as egg donations—increase the odds of getting pregnant.

Growth disorder
Turner syndrome is a growth disorder. That means it affects healthy growth and development, which can result in physical and hormonal abnormalities. Other growth disorders include idiopathic short stature and precocious puberty.

Growth hormone
Human growth hormone is a standard part of treatment for Turner syndrome. The primary purpose of growth hormone is to regain height in girls with TS. Growth hormone is delivered via injections several times a week.

Karyotype test
A karyotype is a blood test that produces an image of your chromosomes. That way, your doctor can identify whether one of your sex chromosomes is missing or partially missing. Turner syndrome is caused by the partial or complete lack of the second female chromosome.

Menopause is a point in a woman's life when she stops having menstrual cycles and her estrogen levels steeply decline. It usually happens between 45 and 55 years of age. Women with Turner syndrome who take estrogen for ovarian insufficiency often stop replacement therapy around age 50.

The ovaries are a pair of endocrine glands that maintain the health of the female reproductive system. The ovaries secrete sex hormones, including estrogen, that are vital to normal reproductive development and fertility. Early ovarian insufficiency is a common characteristic of Turner syndrome.

Puberty marks the end of childhood growth. Growth hormone treatment stops at the completion of puberty—and that's where estrogen replacement therapy takes over. Some girls with Turner syndrome have a normal puberty. Other girls with TS, however, have a delayed—or non-existent—puberty.

Sex chromosomes
Sex chromosomes determine your biological sex. Each chromosome contains genes that control your physical and hormonal features. Men have one X and one Y sex chromosome, while women have two X sex chromosomes. In girls with Turner syndrome, part or all of one of the X chromosome is missing. This leads to abnormal development of certain physical features due to low hormone levels.

Short stature homeobox (SHOX) gene
The short stature homeobox gene plays a large role in determining height and bone growth. It is located on each sex chromosome (in both men and women). When all or part of the second sex chromosome is missing, so is the second SHOX gene. This accounts for the short stature commonly associated with Turner syndrome.

Turner syndrome
Turner syndrome is a growth disorder caused by the complete or partial lack of one of the female sex chromosomes. This results in a range of complications, including stunted growth and development, an increased risk of heart and kidney problems, and infertility. Most commonly, people with Turner syndrome have an abnormally short stature and have early ovarian insufficiency.