Turner syndrome

Turner syndrome (TS) is a genetic disorder that only affects girls. The condition is seen when one of the two X chromosomes* usually found in girls is completely or partially missing, and can prevent children from reaching normal height.

It is important to understand that, with appropriate medical treatment and support, a girl with TS can go on to lead a normal, healthy and happy life.

How will TS affect my child’s height?

Children with TS are often of normal height for the first 2–4 years of their lives but then have a lower than average growth rate. This is due to a reduction in the effect of the growth hormone produced by the body in Turner girls. Later, when they reach puberty, the usual growth spurt fails to occur. Growth hormone treatment started earlier helps Turner patients to achieve a normal height when they are adults. Due to failure of the ovaries to function properly, oestrogen substitution is another important part of hormonal treatment in Turner girls and assists the development of feminine characteristics at puberty. Without treatment during childhood, the average adult height of a woman with TS is about 20cm (6 inches) shorter than other adult women.

How is TS diagnosed?

Many girls are diagnosed at birth or in childhood when a slow growth rate and other features of the condition are identified. Diagnosis is confirmed by a blood test called a karyotype. This is used to analyse the units that make up the child’s chromosomes. The importance of early treatment For a child with TS, the earlier the diagnosis, the better the prospects for treatment. Children who are shorter than normal are often seen by a paediatric endocrinologist, who is a doctor specializing in treating children with growth problems.

Helping children with TS to grow

Daily growth hormone injections can help a child catch up with the growth of other children of the same age during early childhood. Continuing the injections helps maintain normal growth later in childhood, with the final aim of achieving an adult height within the average range. The response to growth hormone treatment varies from one individual to another, but most children who receive treatment over several years will reach a normal or near normal adult height. Recently, it has been found that the dose of growth hormone can be tailored to the needs of individual children in order to help an even greater number reach normal adult height. Ideally the growth hormone injections should start as early as possible and preferably not later than 5 years of age, and should then be continued until growth is complete. If growth hormone treatment is started later, it will still achieve some growth, but the child’s height may not reach the normal range.

Growth hormone injections are normally given once-daily in the evening. At the beginning parents are trained to give these injections when the child is very young. Later on, children can inject themselves with growth hormone when they feel confident enough. Devices are now available that make injecting growth hormone much simpler, more comfortable and less painful. This has been achieved through advances in design such as automated needle insertion and the use of very fine needles. There is a wide choice of devices available, and whilst some require mixing before use and refrigeration once opened, others do not.

To help the doctor select an injection device that matches your requirements, it may help to read the page discussing the features of the various devices.

Other treatments children with TS may receive

Oestrogen replacement therapy is usually started at around 12 years of age, when normal puberty should occur, using low but increasing doses to start breast development. Treatments related to oestrogen and progesterone** are given a little later to induce a monthly period which is necessary to allow shedding of the lining of the womb and keep it healthy. Oestrogen is also important to prevent osteoporosis.

Meeting the challenge of growth problems

If a child doesn’t grow as fast as other children, this can have an impact on the whole family. Many children who are shorter than their schoolmates may experience emotional problems, bullying and difficulties with daily activities such as sports. For these reasons, it’s important to explain to a child that things will improve once the growth hormone treatment has been working for a while. In the meantime, remember to act towards a child according to the age they actually are, not the age they look.

* The X chromosome is one of the two chromosomes in humans which control sexual development (the other is the Y chromosome). Chromosomes contain DNA, the information ‘blueprint’ for life which organises the development and growth of the human body.

** Oestrogen and progesterone are hormones produced by the ovaries at puberty and are important for normal female development.

APROM ID# 1503. December 2009.