Turner's Syndrome

Understanding genes

Turner's syndrome is a genetic condition. This means that there is an abnormality with the genes of the affected person. Genes are passed onto a child from each parent in structures called chromosomes. You have 23 pairs of chromosomes in each cell of your body. Each chromosome contains thousands of genes. Our genes determine how our body functions, what we look like and sometimes what diseases we will get. The genes that control which gender (sex) we become are part of the chromosomes called sex chromosomes. These can be either X or Y chromosomes. We get one sex chromosome from each parent.

Usually, a female has two copies of the X chromosome and a male has one X and one Y chromosome.

What is Turner's syndrome?

Turner's syndrome only occurs in females and is present from the time of conception. It occurs when a female has only one complete X chromosome in each cell. The second X chromosome may be missing entirely or may be incomplete.

Turner's syndrome is named after Dr Henry H Turner who first described the syndrome in 1938.

How common is Turner's syndrome?

Turner's syndrome occurs in about one in 2,500 females. Most of the time, when a conception occurs with one X gene missing, the conception will not develop and a miscarriage will occur early in pregnancy. About 1 in 10 of all miscarriages in the first trimester (the first third of the pregnancy) are due to Turner's syndrome.

There are no known risk factors for Turner's syndrome. It is not more common in girls born to older women and it is very rare to have a second child with Tuner's syndrome.

What are the symptoms for Turner's syndrome?

The symptoms will vary depending on the age of the girl or woman.

Before a girl with Turner's syndrome is born, she may have a problem called lymphoedema. This is when fluid is not able to be transported around the body and organs properly. So, some fluid leaks into tissues and causes swelling. Other symptoms that may develop before birth are thickness of the neck tissue, a neck swelling called a cystic hygroma, or being a small sized baby.

Newborn babies with Turner's syndrome may have lymphoedema of the hands and feet and excess skin of the neck.

As girls become older, a range of symptoms and features may develop. The following are some of the more common:

• Short stature. Most girls with Turner's syndrome will be short for their age.
• Typical facial features. This may include characteristic changes to the eyes, ears, mouth and neck. For example: downslanting eyes, droopy eyelids, prominent earlobes, crowding of the teeth and a short webbed-like neck.
• Bone features. For example, a broad chest with widely spaced nipples, a wide carrying angle (this is the angle between the forearm and the hip when the arm is held by the side), short fingers and nail changes.
• Skin features. About 7 in 10 girls with Turner's syndrome have a lot of moles and obvious blood vessels over the skin.
• Organ abnormalities. About 3 in 10 will have an abnormality with the heart and up to 6 in 10 will have an abnormality of the kidneys or urinary tract.
• Ovarian abnormalities. The ovaries are a pair of glands that lie on either side of the uterus (womb). Each ovary is about the size of a large marble. The ovaries normally make ova (eggs) and various female hormones, in particular, oestrogen. Almost all girls with Turner's syndrome have ovaries that do not work properly. As a result, they may not go through puberty, their breasts may not develop properly, they may not ever get a period, and are likely to be infertile. However, up to 3 in 10 girls will have some changes of puberty and 1 in 200 may be able to get pregnant naturally.

Note: although there are often problems with ovaries, women with Turner's syndrome still have a normal vagina and uterus (womb) and can have a normal sex life.

Are there any complications?

Complications may occur from some of the abnormalities. The most common are as follows:

• Heart and blood vessel complications. For example, heart valves may become faulty, abnormalities on the heart tracing (ECG), or abnormalities of the main blood vessels such as the aorta (the main artery that takes blood from the heart). In some cases the aorta can rupture.
• High blood pressure is quite common.
• Urinary abnormalities. For example, extra tubes from the kidney to the bladder, only one kidney developing, or unusually shaped kidneys. These abnormalities can make urinary tract infections (urine infections) occur more commonly than usual.
• Eye problems. About 8 in 100 girls with Turner's syndrome have colour vision problems and may develop poor vision over time.
• Ear problems. Hearing impairment is common and can be due to chronic (persistent) ear infections or deterioration of the nerves.
• Osteoporosis (thinning of the bones). This may occur later in life as a complication of a lack of oestrogen.
• Other conditions. About 1 in 4 girls with Turner's syndrome develop thyroid problems. A small number develop coeliac disease which is a problem with the gut due to an intolerance to gluten.

How is Turner's syndrome diagnosed?

Turner's syndrome may be suspected by your doctor if a girl has some of the above features. The diagnosis can be confirmed by a test called a karyotype. This is where a sample is taken either from the amniotic fluid around a baby in the womb, or from a blood sample in children. The chromosomes can be studied from the sample. When the chromosomes are studied, if there is one X chromosome missing or if it is incomplete in certain parts, this confirms the diagnosis of Turner's syndrome.

What other tests are needed?

Because there are a number of possible complications of Turner's syndrome, certain tests are usually done when the diagnosis is first made. Some tests are then done on a regular basis, sometimes yearly for the rest of your life. The tests include the following:

• Blood tests. These include a yearly check of thyroid function, liver function, fasting cholesterol and sugar levels. Every 2-4 years, a blood test for coeliac disease is also advised. A blood test for female hormones may also be done to assess whether the ovaries are working or not.
• Hearing assessment. This needs to be done at diagnosis and then every 1-5 years depending on the detection of any hearing loss. If frequent ear infections develop, a specialist review and further treatment may be needed.
• Vision testing. This needs to be done at least at the time of diagnosis or at age one, whichever is later and then repeated as required depending on the issues involved.
• Heart check. This is usually done by a cardiologist (heart specialist) and includes tests such as an ultrasound of the heart (echocardiogram), blood pressure check, tracing of the electrical activity of the heart (electrocardiogram or ECG) and MRI of the heart. Some of these tests will need to be done regularly and some will only be required a few times. It is also very important to have regular monitoring of the size of the aorta, which is the main blood vessel in the body. In some girls with Turner's syndrome, this blood vessel gets wider over time and can burst suddenly (rupture) which may be life threatening. If the size of the aorta is monitored, appropriate treatment, including surgery, can be given to prevent the aorta from bursting.
• Kidney check. An ultrasound scan of the kidneys is usually done when Turner's syndrome is diagnosed to assess for abnormalities with the kidneys and urinary tract.
• Bone assessments. For young children with Turner's syndrome this will mean testing by the doctor for hip dislocations. Teenagers need to be assessed for scoliosis which is a curvature of the spine. Bone density scans to check for osteoporosis are also advised.
• Weight and exercise. Encourage children with Turner's syndrome to eat healthily and exercise regularly in order to keep weight in the healthy range. This is important because of the increased risk of diabetes and heart problems in Turner's syndrome which are more common in overweight people.
• Dental check. Due to the small size of the mouth in some girls with Turner's syndrome, regular dental checks are advised to manage problems with tooth abnormalities. The most common is a problem with dental occlusion - that is, the way the teeth meet when they bite together.

What are the aims of treatment?

As this is a condition caused by abnormal genes, there is no cure for it.

There are several effective treatments for different aspects of the syndrome which aim to minimise the impact of the condition.

What are the treatment options?

These can be divided into medication treatments and non-medication treatments.

Medication treatments

The most important medication treatments are:

• Growth hormone. This is sometimes started as early as 12-24 months of age. It should definitely be started as soon as it is clear that a child is not growing normally due to Turner's syndrome. Growth hormone therapy can be given as a single daily dose, usually at night. It has been shown to increase the final height by as much as 10cm. It may also be combined with another drug to help with growth called oxandrolone (an anabolic steroid). Growth hormone therapy is generally continued until a child reaches a bone age of 14. This means that her bones are the same as the bones of a child without Turner's syndrome at age 14.
• Oestrogen and progesterone. A blood test for these female hormones can indicate if the ovaries are not working and are not producing enough oestrogen. Oestrogen can be given as a tablet, patch or injection. The dose is gradually increased over a few years until a dose is obtained that will give normal oestrogen levels. Progesterone is added later than oestrogen to help produce withdrawal bleeds (like periods). These hormone treatments are usually continued throughout life.

Non-medication treatments

Various treatments may be needed and include the following:

• Psychological therapy. This can be important for a number of girls and women with Turner's syndrome. For example, they may have low self esteem due to their appearance, their social functioning or because they are infertile.
• Sex education. A small number of girls with Turner's syndrome will be able to get pregnant naturally. So, if you have Turner's syndrome and are sexually active, as with any other female you need to be informed about contraception and safe sex practices.
• Infertility. While a small number of women with Turner's syndrome will be able to get pregnant naturally, the vast majority will be infertile. Assisted conception using various forms of IVF may be successful. Regular heart checks before and during pregnancy are essential as pregnancy increases the strain on the heart and blood vessels.
• Learning difficulties. A few girls with Turner's syndrome also have learning problems and so specialised assistance with schooling can help to manage this. However, most girls with Turner's syndrome have normal intelligence.
• Management of lymphoedema. Physiotherapy and support stockings can help to reduce the swelling experienced by some girls with Turner's syndrome.

What is the outlook?

Most girls with Turner's syndrome will be shorter than average and infertile. However, the development of growth hormone treatment in recent years has improved the expected adult height for those treated. The most significant risk faced is that of heart and blood vessel problems. But, regular checks and treatment where necessary has reduced the impact of these complications. Overall, life expectancy is only slightly reduced, most girls with Turner's syndrome have normal intelligence, and most have the potential to lead happy and full lives.

For further information and support

Turner Syndrome Support Society

Tel: 0141 952 8006 Web: www.tss.org.uk