Synopsis: Turner syndrome chromosomal condition describes women and girls with features caused by a partial or complete absence of second sex chromosome.
Turner syndrome (TS) is a form of chromosomal condition that describes women and girls who have features which are caused by either a partial or complete absence of the second sex chromosome.
Turner syndrome (TS) also known as Ullrich-Turner syndrome, gonadal dysgenesis, and 45,X, is a condition in which a female is partly or completely missing an X chromosome. Turner syndrome may be diagnosed before birth (prenatal), during infancy or in early childhood. Turner syndrome can cause a variety of medical and developmental problems, including short height, failure to start puberty, infertility, heart defects, certain learning disabilities and social adjustment problems. The most common feature of Turner syndrome is short stature, which becomes evident by about age 5. Many affected girls do not undergo puberty unless they receive hormone therapy, and most are unable to conceive (infertile).
Dr. Henry Turner was among the first to describe these features in the 1930's, and the syndrome is named after him. TS occurs in about one out of every two-thousand females who are born, as well as in up to as many as ten-percent of all miscarriages.
Diagnosing Turner Syndrome
A diagnosis of Turner syndrome is obtained through a test referred to as a, 'karyotype,' that is commonly done on cells in the amniotic fluid before a person is born, as well as on cells in a person's blood after they are born. A specialist counts the chromosomes in their white blood cells, looking for any abnormalities. Females usually have two, 'X,' chromosomes; with Turner syndrome, the person is missing either all or part of one of their sex chromosomes. Approximately fifty-percent of females with TS present with only one X chromosome, while another third have two X chromosomes, yet part of one X chromosome is missing. Other people with TS present with a mosaic pattern where some of their cells are missing an X chromosome, with other cells that have differing chromosome composition.
While the signs of TS can be subtle, a diagnosis can be achieved throughout a person's lifespan. There are various signs that a karyotype test is needed, to include:
Features and Characteristics of Turner Syndrome
One of the common features of TS is shortness of stature, with the average height of an adult woman who has the syndrome who has not received human growth hormone being 4' 8". People are usually shorter at birth with an average length of 18.5", compared to an average of twenty inches for all girls. The growth failure continues on after the person is born with the majority of females falling below the average growth curve for height during their childhood. Girls with TS who do not receive hormone replacement commonly do not experience a growth spurt during puberty and continue to grow at a slow rate through the age of early-twenties. A number of girls who do receive hormone treatment achieve low-to-average adult height.
Premature ovarian failure:
The majority of females with TS will experience early ovarian failure. Among the general population, the ovaries produce hormones and eggs which are necessary for the development of secondary sexual characteristics. For women with TS, estrogen replacement therapy is needed for feminine body contours, breast development, proper bone development, and menstruation. Approximately one-third of women with TS will present some signs of breast development without estrogen treatment, although a number of them will not complete puberty. Those who do complete puberty many times experience premature ovarian failure, so the majority of women require estrogen from puberty through the average age of menopause. Fertility without reproduction therapy is very rare; only approximately one-percent.
There are a number of features that are characteristic and associated with Turner syndrome. The presence and severity of these features tend to vary greatly among people. These features can include:
Intelligence is another feature that differs among people who have Turner syndrome. On average people with TS have the same overall intelligence and intellectual variance as people in the general population. People with TS, however, many times have difficulty with imagining objects in relation to each other, as well as nonverbal memory and attention. The reason this is important is because it may present issues with sense of direction, math, social skills, or manual dexterity.
Risks of Turner Syndrome
There are some different medical issues that happen more often in people who have Turner syndrome than in those who do not. People with TS should be regularly screened to find out if any of these issues exist. The majority of the conditions may be successfully managed with appropriate medical care.
Approximately one-third of people with TS experience some form of cardiac issue; these problems are mostly left-sided and can include:
People with Turner syndrome need to get an echocardiogram or an MRI in order to evaluate their heart, not only at the time they are diagnosed - but periodically as well, to check for aortic root enlargement. They should also be aware of symptoms associated with dissection of the aorta, which is uncommon but potentially life-threatening. These symptoms include sudden and severe, stabbing, sharp, tearing or ripping chest pains, rapid pulse, intense anxiety, nausea, vomiting, profuse sweating, dizziness, shortness of breath or fainting.
Around thirty-percent of people with TS experience kidney abnormalities, although a number of these abnormalities do not cause them any medical problems. Some of these problems can result in urinary tract infections or hypertension. People with TS should get a renal ultrasound examination when they are diagnosed with the syndrome.
Two other issues that people with TS can experience include hypothyroidism and ear infections. Hypothyroidism caused by inflammation of their thyroid gland commonly happens in people with TS; it can be diagnosed with a blood test and treated with thyroid hormone. Ear infections are also very common in people with TS, particularly in girls between infancy and early childhood. Fifty to ninety-percent of women with TS will develop early nerve hearing loss and might need hearing aids.
Treatment of Turner Syndrome
Treatment of Turner syndrome needs to be based upon the individual's needs.
The person, doctors, and family members should decide which treatment options should be pursued together.
Human growth hormone is a form of treatment that should be considered when a person with TS experiences growth failure or drops below the fifth percentile of the average female growth curve. Estrogen therapy is needed in most women with TS due to ovarian failure. The therapy is commonly started between the ages of twelve and fourteen years of age, although it should be individualized for both pubertal development and growth. Estrogen plays and important part in the maintenance of healthy bone mass; it is recommended that estrogen therapy continue until the age of normal menopause.
Women with Turner syndrome who desire to have children face fertility issues; the most common solution is adoption. Assisted reproduction technology options for women with TS who desire to become pregnant is something that is discouraged because of the increased rate of mortality related to cardiac issues. Reproductive technology options include invitro fertilization with egg donation.