In 1938 an American doctor, Henry Turner, published his first report on seven girls who exhibited similar features of the syndrome he was describing. A syndrome is a set of features in association with each other that result from a stem cause. Though Dr.Turner knew very little about this condition, he did recognize in all of the girls a pattern of short stature and he identified many of the features of this condition. Even though Dr. Turner discovered this condition he was unable to find a cause for it. It was not until 1959 that Dr. C. E. Ford discovered the cause for Turner Syndrome.
Turner Syndrome is a chromosomal disorder that affects approximately 1 in every 2,500 female births. To help you to understand what a chromosomal disorder is, you need to be familiar with cells, chromosomes and genes. Cells are microscopic bodies that make up all living things and are sometimes referred to as “the building blocks of life.” The cells that make up of our bodies are further made up of chromosomes that branch out into short and long arms. Genes are smaller molecules found on chromosomes. These genes determine our hereditary traits and characteristics. Everyone has 22 pairs of normal chromosomes and 1 pair of sex chromosomes in each cell from the moment they are first conceived. Sex chromosomes are the chromosomes that determine your sex as well as influence your physical development. In females all of the chromosomes are X chromosomes. It is when all or part of one of the 23rd pair’s X chromosome is lost during cell division in a fetus that Turner Syndrome results. This condition occurs accidentally and is not at all hereditary. There has been no explanation as to how one of the X chromosomes becomes partially or totally lost. There are three types of Turner Syndrome, which are each determined by their chromosomal abnormality. Three types of chromosomal abnormalities that can occur during cell division cause these three types of Turner Syndrome.
The first type of Turner Syndrome is Monosomy or Classic Turner Syndrome. This is the most common type of Turner Syndrome affecting about 50% of all Turner Syndrome cases. Girls with this form of Turner Syndrome show more of the physical features caused by this syndrome which I will go over later. Monosomy Turner Syndrome occurs when there is one X chromosome from the 23rd pair of chromosomes completely missing in every cell.
The second type of Turner Syndrome is called Mosaicism. Mosaics make up about 30-40% of all turner Syndrome cases. Mosaics tend to show the least number of physical features and medical conditions that are associated with Turner Syndrome. Girls with Mosaic Turner Syndrome will have many cells with the normal 46 chromosomes while some others will have only 45 chromosomes or one slightly altered 46th chromosome. 20% of these females will menstruate naturally but may have early menopause beginning in their late 20’s or early 30’s. Although it is not very common, some females with Mosaic Turner Syndrome may become pregnant and deliver perfectly healthy children.
The third and final type of Turner Syndrome is called Ischromosome. This type of Turner Syndrome occurs in 12-20% of cases. This type of Turner syndrome results from the total or partial loss of the arm of the 46th chromosome. This is the result of the chromosome dividing latitudinally rather than longitudinally causing the tear of the chromosomal arms. The physical and medical features seen in girls with Ischromosome Turner Syndrome are very similar to those with Monosomy turner syndrome.
Turner syndrome can result in a variety of physical features and medical conditions. These features are not exclusive to Turner Syndrome and no female with Turner Syndrome will show all of the features which makes it a very difficult syndrome to detect on it’s own. The most prominent feature of Turner Syndrome is short stature. Another main feature of this condition is underdeveloped ovaries which leads to Turner Syndrome often being called gonadal dysgenesis. Other features of Turner Syndrome include: low hairline at the back of the neck, broad chest, small jaw, a narrow, high arched palate, shorter fingers, soft, spoon shaped fingernails, low hairline and prominent ears. Nearly half of the females with Turner syndrome have a condition known as lymphedema resulting in puffiness in the hands and feet at birth. An equal number of females with Turner Syndrome have a possible constriction between the stomach and intestine which can cause trouble with gulping and vomiting. About 1 out of 10 girls with Turner Syndrome may also have a constricted aorta. This is often diagnosed in the early years of life and can be corrected with a relatively safe surgery. Another possible feature of Turner Syndrome is misshapen kidneys occurring in about 25% of cases. There are many other features of Turner Syndrome which have the potential to lead to greater medical problems. The Eustachian tubes in females with Turner Syndrome do not work properly so middle ear infections are common and hearing may even be impaired later in life. Often, when a female with Turner Syndrome reaches preschool age grommets or tubes may need to be inserted in the ears to allow for the proper drainage of fluid. Hearing exams should be done on a regular basis to monitor the ears and make sure hearing loss does not occur. Ptosis or short sightedness also needs to checked for.
Contrary to previous belief, there is no increased risk of mental retardation in females with Turner Syndrome and they often have a normal intelligence level. Many girls with Turner syndrome will excel at school but some girls may find psychological follow-ups useful in helping to make school related decisions. Their verbal IQ is usually above average but their non-verbal IQ may be lower because they may find visualizing objects in relation to one another more difficult. This may cause problems in math and other tasks involving dexterity or direction. These girls usually learn to read at an early age and have exceptional verbal expression but writing may be slightly delayed. This very long list of features is to help you see the many possible complications as a result of Turner Syndrome. Keep in mind that no female with Turner Syndrome will exhibit all of these features and no one female with Turner Syndrome is alike in terms of the features they show. The difficulty with math and understanding visual-spatial relationships that some girls with Turner Syndrome may experience is called Nonverbal Learning Disability (NLD).
If some of these features are present, especially short stature and underdeveloped ovaries, Turner Syndrome may be suspected and diagnosed. Turner syndrome is most often diagnosed early in life with about one third of females being diagnosed at birth and equal numbers being diagnosed later in childhood or mid-teens. Out of the 3% of births with congenital disorders, Turner Syndrome is considered to be the least severe. Congenital disorders are responsible for about 60% of miscarriages and in about 20% of these miscarriages, Turner Syndrome is considered to be the cause. Any female with Turner Syndrome should feel like “the cream of the crop”, as only 2% of fetuses with Turner Syndrome will survive. A good explanation for this could be that larger than normal fluid amounts build up in the Turner Syndrome fetus. A normal height for a baby at birth is about 50 cm (20 inches) whereas a Turner Syndrome baby may be less than 45cm (18.5 inches).
If a female is suspected of having Turner Syndrome a blood test called a karyotype would be done in which a specialist would count and examine the chromosomes of her white blood cells carefully. Today it is possible to diagnose Turner Syndrome before birth but is most often made after birth. The earlier the diagnosis is made the better because it will help to avoid future complications that can result from the syndrome and parents are then able to cope, understand and deal with these problems. Often diagnosis of Turner Syndrome can be delayed because the girl will tend to grow at a normal rate for her first three to four years before it slows down. Diagnosis is usually sought out for short stature but it is very important to remember that a girl with Turner Syndrome should be treated according to her age and not her height. Another important bit of information to note is that after one pregnancy results in Turner Syndrome there is no increased risk of this happening again.
There is, at the moment, no way to prevent Turner Syndrome from happening or cure it once it occurs. Many of the features of Turner Syndrome can be medically monitored and treated. One feature of Turner Syndrome which can be significantly treated is growth. Over the past 15-20 years there have been three different treatments to combat the slow growth and short stature of girls with Turner Syndrome. All of these treatments include hormone addition therapy. These hormones are estrogen, androgen and synthetic human growth hormone (HGH). Estrogen and Androgen are taken in a tablet form while HGH must be taken by injection. The treatment a girl with Turner Syndrome receives is dependent on her medical complications due to the syndrome. Girls with Turner Syndrome that are nearing the age of 13 may be given a low dose of estrogen for two years. During this time her growth rate may double. Since estrogen, when taken alone, can cause abnormalities of the uterus, progesterone is then included in the therapy. This estrogen and progesterone treatment will go on for the rest of her life from the age of about 15. Estrogen is a female hormone which stimulates the growth of breasts, menstruation and is also important in preventing osteoporosis and hardening of the arteries later in life. Since girls with Turner Syndrome have underdeveloped ovaries they often cannot produce enough estrogen on their own and so estrogen replacement therapy becomes very essential to maintaining good health.
Androgen is sometimes called the “masculizing hormone” which can cause body hair as well as acne common in adolescence. It is fond in both males and females. This hormone is sometimes used to cause a growth spurt, which can be psychologically beneficial for the moment, but it is not thought that this hormone has a large impact to final adult height and it has also been noted that it can stop growth at an earlier age.
Out of all three treatments used the most successful and promising treatment has been HGH. An injection of HGH is given six days a week until the girl grows less than 2 inches a year or her bone age is 14. The growth hormone used is synthetic but it is designed to mimic the growth hormone that is produced in your body and is produced using advanced DNA technology. While on HGH therapy the girl will visit a doctor who specializes in growth (an endocrinologist) every three months. At each visit the endocrinologist will measure her height and weight and test her blood, urine and thyroid to be sure that there are no side effects occurring. Some possible side effects include: diabetes, intercranial hypertension (a build up of fluid surrounding the brain), allergic reactions, slipped femoral emphasis (hip dislocation), papilledema and scoliosis. If any side effects occur the patient will be taken off HGH therapy immediately.
These are some of the basic facts about Turner Syndrome and the hormone treatments used to treat growth in Turner Syndrome patients. It is very important to have a good understanding of this medical condition as well as the treatment plan for it. Doctors (Endocrinologists) should be very helpful about any questions you have upon diagnosis of this condition. The type and symptoms of each girl with Turner Syndrome is different. An early diagnosis is very important to avoid future complications which can be more serious. The prognosis for a Turner Syndrome girl is very good as long as she has regular visits with doctors, has a good understanding of the condition and stays aware of her health. A female with Turner Syndrome can live a perfectly normal life and usually cannot be picked out from a crowd. Turner Syndrome is a health problem but it does not have to become your life or who you are.
Works Cited:
Charney, Susan and Smillie, Andrea. “The X’s and O’s of Turner Syndrome” Toronto: Turner Syndrome Societyof Canada, 1987.
Informed Consent Form for the Use of Commercial Recombination Growth Hormone in Turner Syndrome. IWK Hospital, Halifax, 1997.
Rieser, Patricia. “Turner Syndrome”. Falls Church, Virginia: Human Growth Foundation, 1992.
Rieser, Patricia and Underwood, Dr. Louise. “Turner Syndrome: A Guide for Families”. University of California: 1992.
Stanhope, Dr. Richard. “Turner Syndrome: A Guide for Patients and Parents-series 8”. London: Child Growth Foundation, 1995.
www. Turner-syndrome.com- 2003