Turner syndrome is a genetic condition that only affects females. The condition was named after Dr Henry Turner who discovered it in 1938. It is caused by an abnormal sex chromosome and affects about 1 in every 2,000 baby girls.

Most females are born with two X chromosomes. Turner syndrome occurs when one of the X chromosomes is completely or partially missing. Read more about the causes of Turner syndrome.

Characteristics of Turner syndrome

Girls and women who have Turner syndrome often have a wide range of different medical symptoms and characteristics. However, there are two characteristics that occur in almost all cases of Turner syndrome. They are:

• being shorter than average in height 
• a lack of development of the ovaries (reproductive organs), leading to infertility

As height and sexual development are the two main characteristics of Turner syndrome, the condition is often undiagnosed until a girl reaches school age or puberty (sexual maturity).

The other characteristics of Turner syndrome vary greatly. For example, the condition can cause heart, kidney and thyroid problems, as well as bone disorders and ear problems.

Read more about the symptoms of Turner syndrome.

Treating Turner syndrome

Girls and women with Turner syndrome will need regular health checks throughout their lives and treatment for any symptoms or conditions that develop. However, most are able to lead relatively normal, healthy lives.

The life expectancy of someone with Turner syndrome is slightly reduced, with some studies suggesting that people with the condition may die around 10 years earlier than those without the condition. Read more about treating Turner syndrome.

Types of Turner syndrome

There are two different types of Turner syndrome depending on how much of the X chromosome is missing.

• In classic Turner syndrome an X chromosome is completely missing. 
• In mosaic Turner syndrome a complete X chromosome is only missing from some cells. One X chromosome may be whole and the other may be partially missing or abnormal in some way. 

The symptoms of Turner syndrome vary depending on the age of the girl or woman affected.

Before birth

Babies born with Turner syndrome often have swollen hands and feet caused by lymphoedema.

Lymphoedema is a condition that develops in unborn babies with Turner syndrome. It occurs when excess fluid is unable to drain from the organs and body and leaks into the surrounding tissues, causing swelling.

Other symptoms that may develop before birth include:

• thick neck tissue 
• swelling of the neck (cystic hygroma)
• being a small baby

Common characteristics of Turner syndrome

The two most common characteristics of Turner syndrome are:

• short height
• ovaries that do not function

These two characteristics affect more than nine out of ten females with Turner syndrome. They are described below in more detail.

Short height

Babies with Turner syndrome are usually a normal height until the age of three. After this age, they will have a lower-than-average growth rate.

At puberty, a girl with Turner syndrome will not have the normal growth spurt. Puberty usually happens in girls aged between eight and thirteen. Without treatment, someone with Turner syndrome will usually grow to around 136-147cm (4ft 6in to 4ft 10in). On average, adult women with untreated Turner syndrome are 20cm (8in) shorter than adult women without Turner syndrome. Treatment with growth hormones can reduce this difference (see Turner syndrome - treatment).

Non-functioning ovaries

Ovaries are the pair of reproductive organs in females that produce eggs and sex hormones. During puberty, a girl's ovaries usually begin to produce the sex hormones oestrogen and progesterone. However, most girls who have Turner syndrome will not produce these sex hormones, which means that they:

• may not start their periods naturally as other girls do  
• may not fully develop breasts
• may be infertile (unable to conceive a baby)

Even though many women with Turner syndrome have undeveloped ovaries and are infertile, with hormone replacement therapy their vagina and womb may develop normally. This will mean they are able to have a normal sex life. Girls with Turner syndrome also usually have normal pubic hair growth.

About 3 out of every 10 girls with Turner syndrome experience some physical changes during puberty, and a very small number may be able to become pregnant naturally.

Other symptoms

As well as short height and non-functioning ovaries, there are many other symptoms or characteristics that can affect girls and women with Turner syndrome. Some of these are listed below.

Changes to appearance

Symptoms that affect appearance include: 

• a particularly short, wide neck (webbed neck)
• a broad chest and widely spaced nipples
• arms that turn out slightly at the elbows
• a low hairline
• abnormalities of the mouth, which can cause problems with the teeth
• a large number of moles
• small, spoon-shaped nails 
• a short fourth finger or toe

Eye symptoms

Symptoms that affect the eyes include:

• eyes that slant downwards
• droopy eyelids (ptosis)
• a squint (strabismus) 
• lazy eye (amblyopia) 
• cataracts, which are cloudy patches in the lens (the transparent structure at the front of the eye) 
• short-sightedness (myopia)

Ear symptoms

Symptoms that affect the ears include: 

• low-set ears 
• reoccurring middle ear infections (otitis media) and glue ear during early childhood
• hearing loss, which can develop in later life, is often more severe and develops earlier than the normal age-related decline in hearing

Other conditions

Symptoms that affect the rest of the body include the following. 

• A heart murmur, which is where your heart makes a whooshing or swishing noise between beats. This is sometimes associated with narrowing of the main blood vessel in the heart (aorta).
• An underactive thyroid (hypothyroidism), which occurs in around 10-30% of women with Turner syndrome. Regular blood tests are needed to detect and treat it early if necessary.
• High blood pressure (hypertension) also needs to be checked regularly.
• Osteoporosis (brittle bones), which may develop due to the lack of oestrogen. Hormone replacement therapy can often help to prevent osteoporosis.
• Scoliosis (abnormal curvature of the spine) occurs in about 1 in 10 teenage girls with Turner syndrome and should be screened for.
• Diabetes, which is a condition caused by too much glucose in the blood. 
• Lymphoedema, which, as well as affecting unborn babies, can also occur at any age. 
• Bleeding in the digestive system (gastrointestinal bleeding) is due to abnormalities in the blood vessels in the intestines. Other digestive conditions, such as Crohn's disease and ulcerative colitis, are also more common in females with Turner syndrome.
• Kidney and urinary tract problems, which can increase the risk of developing urinary tract infections.

Learning difficulties

Most girls with Turner syndrome have good language and reading skills. However, some have behavioural, social and specific learning difficulties that are often overlooked by doctors that can cause great anxiety to the parents. They include: 

• problems with social intelligence 
• problems with spatial awareness and numeracy 
• attention and hyperactivity problems

Social intelligence

About a third of children with Turner syndrome have difficulties understanding social relationships because of the way their brain develops.

Affected girls may find it hard to sustain friendships, and in later life may experience relationship problems at home and at work. They tend to be anxious and eager to please. This can mean girls and women are vulnerable in social settings, as they may be naive or lacking in experience for dealing with a particular situation. As adults, many women with Turner syndrome prefer to work with children.

Spatial awareness and numeracy

Spatial awareness is understanding where you are in relation to other people or objects. More than 8 out of 10 females with Turner syndrome have difficulty understanding spatial relationships. This may cause problems when learning to drive, or when following directions on a map.

A similar number have some degree of difficulty learning or understanding maths, this is known as dyscalculia. Girls may find it difficult to understand even simple mathematical rules, and their concept of numbers is not well developed. At school, teachers may not fully appreciate the problem, which can cause considerable stress.

Attention and hyperactivity problems

Typically, girls with Turner syndrome will go through a phase in childhood that involves: 

• physical overactivity, such as constant fidgeting and restlessness 
• acting impulsively, such as breaking rules or having no sense of danger  
• having a short attention span and being easily distracted

Attention and hyperactivity problems usually begin when the girl is a toddler. However, they may not be a serious problem until the girl starts school at four or five. Girls with Turner syndrome may have difficulty settling in class.

These may be symptoms of attention deficit hyperactivity disorder (ADHD), but treatment for this condition does not work as normal in cases of Turner syndrome. This can be challenging to deal with, but symptoms generally improve as the girl gets older. The physical hyperactivity usually reduces around the time the girl starts secondary school at 11. However, the problems with inattention can last longer, until the girl is a teenager.

There are several different ways of diagnosing Turner syndrome, depending on the age of the female who may have the condition.

Diagnosis during pregnancy and birth

Turner syndrome is sometimes suspected in pregnancy during a routine ultrasound scan. This is a procedure that uses high frequency sound waves to create an image of the developing baby. Lymphoedema, a condition that causes swelling of the body’s tissues, can affect unborn babies with Turner syndrome and may be visible on an ultrasound scan.

If Turner syndrome is suspected, the diagnosis may be confirmed with a further test such as:

• chorionic villus sampling, where a sample of cells taken from the placenta (the organ that links the mother’s blood supply with her unborn baby’s) is tested for genetic conditions 
• amniocentesis, where a sample of amniotic fluid (the fluid that surrounds the developing baby in the womb) is tested for genetic conditions

In some cases, Turner syndrome can be diagnosed at birth as a result of heart or kidney problems, or swelling of the hands and feet (lymphoedema).

Diagnosis in childhood

Turner syndrome may be suspected if a girl has the typical characteristics of the condition, such as a wide (webbed) neck, a broad chest and widely spaced nipples. Read more about the symptoms of Turner syndrome.

Short height and undeveloped ovaries are the two main clinical features of Turner syndrome.

Many girls with Turner syndrome are diagnosed during early childhood when a slow growth rate and other common features of the condition are identified. However, in some cases, a diagnosis is not made until later when puberty does not occur.

Karyotype

A diagnosis of Turner syndrome is usually confirmed using a blood test called a karyotype. This either involves taking a sample of amniotic fluid while the baby is still inside the womb, or taking a blood sample from a child who is thought to have the condition.

Chromosomes in the amniotic fluid or a blood sample are analysed in a laboratory. Turner syndrome is confirmed if one of the X chromosomes is absent or incomplete. Read more about the causes of Turner syndrome.

Turner syndrome cannot be cured. However, many treatments are available for the different characteristics of Turner syndrome, such as short stature, sexual development problems and learning difficulties.

Regular health checks

For girls and women with Turner syndrome, regular health checks and early preventative care and treatment are very important. This is because of the risk of complications.

Some areas have special Turner syndrome clinics that employ several specialists (see below). If a girl or woman is diagnosed with Turner syndrome, the following areas may be monitored throughout her life. 

Hearing and ears

During childhood, middle ear infections (otitis media) are more likely to develop and need to be treated quickly. About half of all women with Turner syndrome lose their hearing at a faster rate compared with normal age-related decline.

Blood pressure 

High blood pressure (hypertension) is quite common in women with Turner syndrome, so it is important that blood pressure is regularly checked and that treatment is provided, if necessary.

Thyroid gland

Thyroid function tests can be used to asses how well the thyroid gland is working, as there is also a slightly higher risk of having an underactive thyroid (hypothyroidism). 

Glucose levels

The glucose levels in blood or urine may be checked to screen for diabetes (a condition caused by too much glucose in the blood).

Bone mineral density (BMD)

As women with Turner syndrome are at increased risk of osteoporosis (brittle bones), bone mineral density can be measured with a dual energy X-ray scan, which is usually known as a DEXA scan.

If someone is diagnosed with any of these conditions, appropriate treatment can be given.

Growth hormone therapy

An endocrinologist (specialist in hormone conditions) will be able to carry out tests and checks on a regular basis. They will also be able to recommend appropriate treatment, such as growth hormone therapy.

Growth hormone therapy should be given to a girl with Turner syndrome as soon as it becomes obvious that she is not growing normally. It will help to prevent short height during adulthood.

Growth hormone therapy is usually started at around five or six years of age. However, if Turner syndrome is not diagnosed until the girl is older, it may be started later. Growth hormone therapy usually continues until the girl is 15 or 16.

Somatropin

The National Institute for Health and Clinical Excellence (NICE) has produced guidance about somatropin, the growth hormone that is used to treat Turner syndrome. NICE has said that treatment with somatropin should be started and monitored by a paediatrician with expertise in growth hormone disorders in children. As the girl gets older, her care may be transferred to an adult endocrinologist (see box to the right).

There are seven different types of somatropin made by different pharmaceutical companies. Which one is used will depend on which product is most likely to suit the girl with Turner syndrome.

Treatment with somatropin should be stopped if: 

• there is not enough growth in the first year of treatment 
• the girl is near to her final height and has grown less that 2cm (0.8in) in a year 
• the girl is unable to continue taking the medicine, for example, due to side effects
• the girl reaches her final height

Somatropin is usually given daily as a single injection. The girl’s parents can administer the injection or the girl can learn to do it herself. The dose will depend on the girl’s size.

Side effects of somatropin can include:

• headaches
• visual problems
• nausea and vomiting
• a build-up of fluid that can cause swelling in the lower limbs, such as the feet (peripheral oedema)
• joint pain 
• muscle pain  
• carpal tunnel syndrome, which is a condition that causes pain, numbness and a burning or tingling sensation in the hand and fingers 
• pins and needles 
• antibody formation, which is when the body responds to the medicine by producing proteins that usually fight infection 
• underactive thyroid  
• reactions at the site of the injection 
• insulin resistance, which is where the body’s cells do not react to insulin (a hormone that moves glucose out of the blood and into cells, where it is broken down to produce energy)
• high levels of glucose in the blood (hyperglycaemia)
• low levels of glucose in the blood (hypoglycaemia)

The studies that were reviewed by NICE found that somatropin increased height by around 5-9cm (2-3.5in).

Oestrogen and progesterone replacement therapy

Following tests and checks, an endocrinologist may also recommend oestrogen and progesterone replacement therapy.

Oestrogen and progesterone are the female sex hormones that are responsible for a girl’s sexual development. Oestrogen is also important in preventing osteoporosis.

However, in girls with Turner syndrome, the sexual hormones do not work properly and the ovaries (the female reproductive organs) do not produce enough oestrogen. A blood test can be used to check oestrogen levels and determine whether the ovaries are functioning properly.

Girls and women with Turner syndrome will usually require regular sex hormone treatment until they are around 50 years of age. After this time, the body normally stops producing the hormone oestrogen and a woman experiences the menopause (when monthly periods stop).

Oestrogen

Oestrogen replacement therapy is usually started at the time of normal puberty or just after. In girls, the average age for the start of puberty is 11. However, it may be recommended that girls start to take oestrogen a little later, between the ages of 12 and 15, because starting treatment too early may reduce the final height that the girl is able to grow to.

Oestrogen can trigger the changes that usually happen during puberty, such as breast development, which, otherwise, girls with Turner syndrome may not experience.

Oestrogen can be given as a tablet, patch or injection. Low doses are used to start with before being gradually increased until the girl’s oestrogen levels become normal.

Progesterone

Progesterone is usually started slightly later than oestrogen and can encourage periods to start.

Fertility

Most women with Turner syndrome are infertile. However, there is a small chance that pregnancy will occur naturally. Therefore, girls and women with Turner syndrome should be made aware of suitable methods of contraception and how to practise safe sex.

In vitro fertilisation (IVF)

Assisted conception techniques, such as in vitro fertilisation (IVF), may be recommended for women with Turner syndrome who want to have children.

If a women has Turner syndrome and becomes pregnant, she will require regular heart checks because the heart and blood vessels will be put under extra strain during pregnancy.

Psychological therapy

Some girls and women who have Turner syndrome may develop psychological problems, such as low self-esteem or depression, due to their physical appearance or infertility. Psychological therapy, such as counselling, may be recommended to treat these problems.

Learning difficulties

Most girls with Turner syndrome have a normal intelligence level, although some may have learning difficulties and require extra tuition at school or at home. The paediatrician treating a girl with Turner syndrome may not ask about these specific problems, so it is important to seek help if your daughter is affected.

If a girl with Turner syndrome has learning difficulties, her parents can speak to their GP or health visitor, or a teacher at the child’s school or nursery. The school should follow guidelines on how to assess and meet the child’s special educational needs to ensure she gets the right support.

As Turner syndrome is quite rare, special education departments may not have come across a case before and may not know the best way to provide support. For example, girls with Turner syndrome may need extra time to complete tasks, but other methods of help will depend on their specific problems.

Specialists involved in treating Turner syndrome