Introduction
Turner syndrome is a genetic disorder that exclusively affects individuals assigned to females at birth (AFAB) and is characterised by the partial or complete absence of an X chromosome (sex chromosome).1 People normally have two sex chromosomes – with individuals assigned male at birth (AMAB) having one X and one Y chromosome (XY), and individuals AFAB having two X chromosomes (XX). Turner syndrome involves an abnormality of an X chromosome. As such, when one of an AFAB individual’s X chromosomes becomes abnormal, their risk of developing Turner syndrome increases.
Newborns with Turner syndrome typically present with the following symptoms:1,2,3
- Swelling of the hands and feet (congenital lymphedema)
- Webbed neck
- Short stature (even when they grow)
- Low hairline at the nape of the neck
- Bone deformity (cubitus valgus) wherein the forearm is angled away from the body
- Ear abnormalities (i.e., the ears are positioned lower than the head)
- Underdeveloped ovaries
Since short height and poor sexual development are the two most common symptoms of Turner syndrome, the disorder may not be diagnosed until puberty (8-14 years of age), when it presents as a failure to show sexual development.2
Most patients with Turner syndrome have normal intelligence but have cognitive impairments, such as problems with spatial visualisation (e.g. having difficulty determining the relative position of objects in space). These learning disabilities can affect their ability to learn mathematics, for example.3
There is currently no cure for Turner syndrome; however, some treatment options exist to minimise or manage its symptoms.
Medical management of turner syndrome
Growth hormone (GH) therapy
Growth hormone (GH) is produced by the pituitary gland, which is located in the brain4. GH is responsible for many bodily functions, but a common one is growth and development.
Growth hormone (GH) therapy involves administering GH to individuals with a GH deficiency or certain disorders that affect their height or ability to grow, such as Turner syndrome. It should be noted that Turner syndrome does not typically cause GH deficiency, but people with the condition may benefit from the treatment.1 Individuals whose height falls in the bottom 5% for their age are typically recommended for GH therapy, and they should remain on the treatment until they reach their adult height, where there is no more potential for them to grow.1
In a laboratory setting, growth hormones can be artificially produced using genetic engineering techniques.5 Artificial GH produced in this way is known as recombinant GH and is simply a synthetic version of the hormones naturally made by the body. The U.S. Food and Drug Administration (FDA) has approved the use of recombinant GH for the treatment of individuals with Turner syndrome.5
A common growth hormone used for the treatment of Turner syndrome is somatropin, which has been shown in research studies to increase height by 5cm.6 Somatropin is given as an injection, which can either be administered with the help of a parent, or the patient themself.
Hormone replacement therapy
Individuals with Turner syndrome usually do not produce the hormone oestrogen, which is responsible for bringing about normal puberty. Oestrogen replacement therapy is a form of hormonal replacement therapy that is a standard treatment for patients with Turner syndrome. The main aim of oestrogen replacement therapy is to induce puberty and maintain healthy sexual development.7 Essentially, the main purpose of the therapy is to mimic the normal process of puberty.
The ovaries are the female reproductive organs responsible for the production of the sex hormone oestrogen. Ovarian insufficiency (when the ovaries do not function properly) is common among individuals with Turner syndrome.7 If the ovaries are nonfunctional, they will not be able to produce oestrogen properly, resulting in aberrant sexual development.
Almost all individuals with AFAB need oestrogen to stimulate normal sexual development. Whilst ~15% of patients with Turner syndrome experience spontaneous puberty, they are still at risk of ovarian insufficiency in later life if the ovaries cannot reliably produce sufficient levels of oestrogen.1 Similarly, many individuals with Turner syndrome experience delayed, absent, or incomplete puberty - causing them to have underdeveloped breasts or issues with menstruation. As such, oestrogen replacement therapy is often needed to ensure healthy and complete sexual development.7 Progesterone supplementation may also be provided to support the menstruation cycle.1
Patients are usually recommended oestrogen replacement therapy at the age of 11.1 Oestrogen replacement therapy is known to provide protection against bone loss, also known as osteoporosis, or the deterioration of bone.
Thyroid hormone replacement
Approximately 10-30% of patients with Turner syndrome develop issues with their thyroid - a small gland in the neck responsible for the production and secretion of various hormones.8 Common thyroid diseases include primary hypothyroidism, which is characterised by decreased production of thyroid hormones (resulting in symptoms such as intolerance to colds, weight gain and body aches) and Hashimoto’s thyroiditis, which is characterised by inflammation of the thyroid gland due to the immune system mistakenly attacking this vital organ.
Thyroid hormone replacement therapy involves using the synthetic thyroid hormone levothyroxine to replenish thyroid hormone stores in the body, restoring normal bodily functions.8
In vitro fertilisation (IVF)
Most patients with Turner syndrome are not able to conceive and are considered infertile.6 However, in vitro fertilisation (IVF) is often used to help patients with fertility problems. The process of IVF involves removing an egg from the ovaries and fertilising it with sperm in a laboratory.9 The fertilised egg (now considered an embryo) is then inserted into her womb and left to develop as in a traditional pregnancy.
Individuals with Turner syndrome may be able to undergo IVF with a donor egg.1 However, the patient will need to be closely monitored by consultants to ensure no complications occur, as they are at a higher risk of complications.5
Psychological support
Some patients may develop depression and require psychological support. Individuals with this condition may find it hard to interact with others in social settings or feel self-conscious about their physical characteristics in comparison to their peers. Common psychological therapy routes include counselling and cognitive behavioural therapy (CBT).6
A psychologist may be able to provide guidance to patients with Turner syndrome on self-esteem issues or any specific learning difficulties.10
Summary
Turner syndrome is a genetically inherited condition characterised by the partial or complete absence of one X chromosome. Consequently, individuals assigned females at birth are more commonly affected than males since they possess the chromosomal combination XX, whereas males have XY.
Individuals with Turner syndrome often present with changes in their physical characteristics, such as short stature, webbed neck, unusually-angled forearms, and underdeveloped ovaries. Since the condition affects sexual development and height, the disorder may not be recognisable until puberty. Most patients with Turner syndrome have normal intelligence; however, some may encounter challenges in learning mathematics due to difficulties with calculations.
There is currently no cure for Turner syndrome, but a variety of treatment options exist to help manage symptoms and bring about normal, healthy sexual development. A common treatment option is growth hormone (GH) therapy which aims to help increase height in individuals with Turner syndrome. Oestrogen replacement therapy is a form of hormone replacement therapy that instructs the body to mimic the normal process of puberty, whilst thyroid replacement therapy aims to replace the missing hormones by administering synthetic thyroid hormones such as levothyroxine, which helps prevent thyroid-related complications like hypothyroidism.
Turner syndrome makes it difficult for affected individuals to conceive, and many are infertile. Assisted reproductive technology such as in vitro fertilisation (IVF) with the use of a donor egg and implanted pregnancy may be able to have children. Additionally, Turner syndrome patients may require psychological support in the form of cognitive behavioural therapy and counselling.
FAQs
Do people with turner syndrome need to undergo surgery?
Some patients with Turner syndrome (TS) are born with a heart defect, known as coarctation of the aorta, which is characterised by the narrowing of the aorta (i.e., the largest artery in the human body). This complication may be fixed with surgery.
What happens if you don’t treat Turner syndrome?
Individuals with Turner syndrome who don’t receive treatment will be shorter than their peers, typically around an average adult height of under 5 feet.
References
- Shankar Kikkeri N, Nagalli S. Turner Syndrome. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 [cited 2024 Apr 1]. Available from: http://www.ncbi.nlm.nih.gov/books/NBK554621/.
- NHS UK. Turner syndrome [Internet]. 2018 [cited 2024 Apr 1]. Available from: https://www.nhs.uk/conditions/turner-syndrome/.
- NICHD - Eunice Kennedy Shriver National Institute of Child Health and Human Development. What are the symptoms of Turner syndrome? [Internet]. 2021 [cited 2024 Apr 1]. Available from: https://www.nichd.nih.gov/health/topics/turner/conditioninfo/symptoms.
- GOSH Hospital. Growth hormone deficiency [Internet]. [cited 2024 Apr 1]. Available from: https://www.gosh.nhs.uk/conditions-and-treatments/conditions-we-treat/growth-hormone-deficiency/.
- NORD. Turner Syndrome - Symptoms, Causes, Treatment [Internet]. [cited 2024 Apr 1]. Available from: https://rarediseases.org/rare-diseases/turner-syndrome/.
- NHS UK. Turner syndrome - Treatment [Internet]. 2017 [cited 2024 Apr 1]. Available from: https://www.nhs.uk/conditions/turner-syndrome/treatment/.
- Health Central. Growth Hormone Deficiency Diagnosis [Internet]. 2014 [cited 2024 Apr 3]. Available from: https://www.healthcentral.com/condition/growth-disorders/growth-hormone-deficiency-diagnosis.
- Turner Syndrome Foundation. Thyroid [Internet]. 2024 [cited 2024 Apr 3]. Available from: https://turnersyndromefoundation.org/what_is_turner_syndrome/autoimmune-diseases/thyroid/.
- NHS UK. IVF [Internet]. 2017 [cited 2024 Apr 3]. Available from: https://www.nhs.uk/conditions/ivf/.
- Turner Syndrome Support Society. Treatment [Internet]. [cited 2024 Apr 3]. Available from: https://tss.org.uk/index.php/facts/treatment.