Turner Syndrome

What is Turner Syndrome?

Turner syndrome is a condition that results from the absence or structural alteration of one of the two normal X chromosomes. Also referred to as monosomy X, it may affect various parts of your body, with short stature and diminished ovarian function being its recognised features. Some people may also experience kidney abnormalities, congenital heart problems, thyroid disorders, hearing difficulties, and fertility problems.

Turner syndrome can be different in different people. Some have a number of associated health problems, whereas others have only a few noticeable features.

What are the Types of Turner Syndrome?

Turner syndrome can occur because one X chromosome is completely or partially missing or structurally altered. The chromosome pattern can vary between individuals, which is why the signs and associated health problems can differ considerably. The common types of Turner syndrome are as follows:

How Common is Turner Syndrome in India?

Turner syndrome is estimated to occur in approximately 1 in 2,000 or 1 in 2500 live female births, depending on its type.

A 2025 analysis of Global Burden of Disease (GBD) 2021 data estimated 45,941 cases of Turner syndrome among children aged 0 to 14 years in India, with a 95% uncertainty interval of approximately 35,105 to 61,430 cases.

India had the highest estimated number of Turner syndrome cases among children in this age group across the countries included in the analysis.

What are the Symptoms of Turner Syndrome?

The symptoms of Turner syndrome vary from one person to another, depending on their chromosome pattern and any other health conditions. Some symptoms may appear in infancy or childhood, while others become more noticeable at puberty.

The early warning and advanced symptoms of Turner syndrome are given below:

Diseases Similar to Turner Syndrome

Some chromosomal and genetic disorders cause features similar to those in Turner syndrome, including delayed puberty, short stature, fertility problems, or some physical differences. However, the genetic causes and health consequences are different in all these cases.

The following table compares Turner syndrome with other chromosomal and genetic disorders like Klinefelter syndrome and Noonan syndrome that show similar features:

Turner Syndrome vs. Klinefelter Syndrome vs. Noonan Syndrome

What Causes Turner Syndrome?

Turner syndrome occurs because one X chromosome is completely or partially missing or structurally altered. The chromosome difference can be present in all cells or only in a proportion of cells, as in the case of mosaic Turner syndrome.

The common causes of Turner syndrome are as follows:

• Complete Loss of an X Chromosome: In classic 45,X Turner syndrome, one X chromosome is absent from essentially all cells tested.

• Mosaicism: Some individuals have two or more cell lines, such as 45,X and 46,XX. The clinical features can vary depending on the chromosome patterns present.

• Structural Changes: A portion of the X chromosome may be deleted, rearranged, or present as a ring chromosome or another structural variant.

• Variation Between Cell Lines: The chromosome abnormality may not be present in every cell, which can make diagnosis more complex and contribute to differences in symptoms.

Turner syndrome usually results from a random chromosomal event during the formation of reproductive cells or during early cell division. It is generally not caused by anything the parents did before or during pregnancy.

What are the Risk Factors for Turner Syndrome?

Turner syndrome usually occurs because of a random chromosomal change and is not linked to a person's lifestyle, diet or other preventable factors. Most cases are not inherited from either parent. Therefore, there are no established lifestyle-related risk factors that can be modified to prevent Turner syndrome.

However, certain circumstances may be relevant when Turner syndrome is suspected or when assessing an individual's chromosome findings. These include:

• Chromosomal Abnormality: Turner syndrome results from the loss or structural alteration of X chromosome material. The specific chromosome pattern can influence the associated health features.

• Mosaicism: Having different chromosome patterns in different cells can result in a varied clinical presentation.

• Presence of Y Chromosome Material: A small proportion of people with Turner syndrome may have Y chromosome material. Its presence is clinically important because it can increase the risk of gonadoblastoma and may require further specialist evaluation.

• Family History of Chromosomal Rearrangement: Although Turner syndrome itself is usually not inherited, rare structural chromosome abnormalities can have different inheritance patterns. A family history of chromosomal rearrangements may therefore warrant genetic counselling in selected cases.

A person's age, physical activity, diet, occupation, or everyday lifestyle does not cause Turner syndrome. Parents should also be reassured that Turner syndrome is generally not caused by anything they did before or during pregnancy.

When Should I See a Healthcare Provider?

Talking to a doctor is important if you or your child has shown features associated with Turner syndrome. A healthcare provider performs an initial assessment and testing to identify associated health concerns and monitor this condition properly. Seek medical advice if:

• Growth is shorter than expected for age

• Puberty is delayed or does not begin normally

• Menstrual periods do not start at the expected age

• Fertility or reproductive development concerns

• Swelling on hands or feet, especially in childhood

• Physical features associated with Turner syndrome, such as a broad chest or webbed neck

• A congenital kidney or heart abnormality has been identified

• Any concerns related to blood pressure, thyroid function, hearing, or bone health

• Turner syndrome is suspected based on physical findings or prenatal testing

How is Turner Syndrome Diagnosed?

Turner syndrome is diagnosed through chromosome analysis along with a clinical assessment and investigations for associated health conditions. Diagnosis may occur during pregnancy, childhood, adolescence, or adulthood, depending on the features that lead to medical evaluation.

The common diagnostic tests used to diagnose Turner syndrome are as follows:

Diagnostic Summary Table

How is Turner Syndrome Treated and Managed?

There is currently no treatment that can correct the underlying chromosome abnormality in Turner syndrome. Treatment focuses on supporting growth and pubertal development, replacing hormones when required, monitoring cardiovascular and other organ-system risks, preserving or assessing fertility where appropriate, and treating associated medical conditions.

Management is individualised and usually involves more than one healthcare specialist. The common treatments prescribed by doctors to individuals with Turner syndrome are as follows:

Common Medicines Used to Treat Turner Syndrome

Medicines used in Turner syndrome depend on the individual's age, symptoms, and associated health conditions. They are prescribed and monitored by healthcare professionals rather than used as a standard treatment package for every person. Some common medicines recommended by doctors are as follows:

• Somatropin: It may be prescribed for eligible children to support linear growth.

• 17β-Oestradiol: Estrogen replacement may be used to initiate and maintain pubertal development and support bone health when ovarian function is insufficient.

• Progesterone: A progestogen may be added after adequate estrogen exposure when the uterus is present to protect the endometrium.

• Levothyroxine: May be prescribed when Turner syndrome is associated with hypothyroidism.

• Antihypertensive medicines: Medicines such as angiotensin receptor blockers, ACE inhibitors or calcium-channel blockers may be prescribed when high blood pressure is diagnosed.

The type, dose and duration of treatment vary between individuals. Hormone therapy, growth hormone and medicines for associated conditions should be used only under appropriate medical supervision.

Note: Hormone therapy and medicines should only be taken under medical supervision. Treatment may depend on the age, symptoms, chromosome pattern and associated health conditions.