Turner syndrome

What is Turner syndrome?

Turner syndrome (TS) is a condition that affects only people with female reproductive systems. It happens when there is the presence of one X chromosome and part or all of the other sex chromosome is missing. Sometimes, more complicated chromosomal patterns are seen.

Children with TS often have a similar set of features including short stature, lack of sexual development at puberty and webbing of the neck. TS affects one in every 2,000 to 2,500 female babies. Most children with TS can expect to lead healthy, productive and happy lives.

Common features of Turner syndrome

People with TS may share various common features. How and when these features develop and how severe these problems are vary amongst those affected. Physical and mental development also varies for every child with TS. Sometimes a child with TS will not show any significant signs of the condition as infants or children. It is not uncommon for some to be diagnosed during adolescence if they do not start puberty or stall in their pubertal development. Others may find that their menstrual cycle becomes irregular or they experience infertility as a young adult, which leads to suspicion and diagnosis of TS. The following are common features of TS across childhood:

Infants

• smaller size
• heart and blood vessel abnormalities (up to 50% are born with a congenital heart condition)
• extra skin folds at the side and back of the neck, webbed or short neck
• small and puffy hands and feet
• kidney abnormalities

School-aged children

• slower growth
• smaller in stature compared with peers
• recurrent ear infections
• hearing problems
• eye and vision problems
• learning difficulties, hyperactivity, social interaction issues
• wide-set nipples
• broad chest
• low hairline at the back

Adolescents

• does not develop breast tissue, or breast development and puberty do not progress (stall)
• shorter stature compared to peers (with no growth spurt during puberty)
• does not menstruate at the expected age
• development of new health issues/conditions

Adults

• irregular menstruation
• fertility problems
• heart problems
• high blood pressure
• development of thyroid disease, celiac disease

Causes

Most females are born with two complete X chromosomes. The X chromosomes are the sex chromosomes for females. TS is caused by the absence of all or part of the second sex chromosome in some or all of the cells of the body.

Two full X chromosomes are needed for the development of a fully functional female reproductive system and normal linear growth and development. Some females inherit only one X chromosome (45%), while others have parts of the second sex chromosome but only in some cells (this is called mosaicism), or they have structural anomalies of one of the X chromosomes. It is believed that this is caused by a spontaneous error in cell division at conception or shortly after. TS is generally not an inherited condition except in rare cases.

Turner syndrome karyotype

How is Turner syndrome diagnosed?

Your child’s health-care provider will conduct a physical examination. They will then arrange a series of tests. Most children are diagnosed when they are very young, although people can be diagnosed with TS at different ages or stages of life.

Some babies may be diagnosed before birth. Fetal ultrasound during pregnancy can give information about the possibility of TS. Health-care providers can also test for TS by taking a sample of blood, amniotic fluid or other tissue. This test is called a karyotype. It is used to analyze chromosomes and determine if there is an underlying chromosomal abnormality.

How is Turner syndrome treated?

While there is no cure for TS, the conditions associated with TS can be managed.

Some children are treated with hormones to stimulate puberty and growth if needed. Children with TS tend to follow a specific growth pattern (TS growth charts are available to view online). Your child may be referred to a specialist if they have heart problems or other complications. Once diagnosis is confirmed, your child’s health-care providers will help with education, counselling and ongoing health surveillance. Your child may need to seek the support of other children with this condition. Groups like the Turner Syndrome Society of Canada can offer resources and family support.

Prevention

There is no known way to prevent TS. 

Health issues and conditions associated with TS

Many children with TS lead healthy lives. Some children, however, are diagnosed with or develop other associated medical conditions, including:

• eye problems (e.g., strabismus, amblyopia, myopia (nearsightedness), hyperopia (farsightedness), colour blindness)
• chronic or recurrent middle ear infections and hearing loss
• high arched palate with associated dental and orthodontic problems (dental crowding)
• feeding problems in infancy and childhood
• hypothyroidism
• heart or blood vessel abnormalities, some of which can be life threatening
• high blood pressure
• kidney and urinary tract abnormalities
• liver function abnormalities
• metabolic issues (diabetes, high cholesterol)
• curvature of the spine (scoliosis)
• autoimmune conditions (celiac disease, thyroid disease or inflammatory bowel disease)
• overweight and obesity
• infertility
• bone conditions, lower bone density (osteoporosis)
• lymphedema (swelling or puffy or broad hands or feet)

Additionally, psychosocial and educational problems may include:

• difficulty with social skills
• learning challenges typically affecting visual-motor and visual-spatial skills

Your child will need ongoing medical care and monitoring as the risks for developing additional issues increase with age.

When to seek medical assistance

If you suspect your child may have TS, make an appointment with your child's health-care provider.

Resources

Clinical practice guidelines for Turner syndrome