Turner Syndrome

Overview

Turner syndrome is a genetic condition that affects only females and results from a complete or partial absence of one of the two X chromosomes. It is also known as monosomy X or 45,X. The syndrome can cause a variety of medical and developmental problems, including short stature, delayed puberty, infertility, heart defects, and certain learning difficulties. Turner syndrome is relatively rare, occurring in approximately 1 in 2,000 to 1 in 2,500 live female births.

Causes

Turner syndrome is caused by a chromosomal abnormality involving the X chromosome. In most cases, the condition results from the complete absence of one X chromosome (monosomy X), but some individuals may have structural abnormalities of one X chromosome or a mixture of normal and abnormal cells (mosaicism). The chromosomal error usually occurs randomly during the formation of reproductive cells or in early fetal development. It is not typically inherited from a parent.

Symptoms

The symptoms of Turner syndrome can vary widely among individuals, and some girls may not show obvious signs until later in childhood or adolescence. Common features include:

• Short stature

• Webbed neck (extra folds of skin on the neck)

• Low hairline at the back of the neck

• Broad chest with widely spaced nipples

• Lymphedema (swelling) of hands and feet, especially at birth

• Delayed puberty or absence of menstruation

• Infertility due to underdeveloped ovaries

• Heart abnormalities, such as coarctation of the aorta

• Kidney abnormalities

• Hearing loss

• Normal intelligence but possible learning difficulties, especially with spatial reasoning or mathematics

Diagnosis

Turner syndrome may be suspected based on physical features and developmental delays, but it is confirmed through genetic testing. Common diagnostic methods include:

• Karyotype analysis: A blood test that examines the chromosomes and can identify missing or abnormal X chromosomes.

• Prenatal testing: Turner syndrome can be detected before birth through procedures such as amniocentesis or chorionic villus sampling (CVS), especially if abnormalities are seen on an ultrasound.

• Hormone testing: To assess ovarian function and hormone levels in adolescent girls with delayed puberty.

Treatment

There is no cure for Turner syndrome, but many of the associated health issues can be managed effectively. Treatment may include:

• Growth hormone therapy: To increase height in children with short stature, typically starting in early childhood.

• Estrogen replacement therapy: Initiated around the age of puberty to promote the development of secondary sexual characteristics and maintain bone health.

• Fertility treatment: While most women with Turner syndrome are infertile, assisted reproductive technologies using donor eggs may be an option for some.

• Regular monitoring and treatment of heart, kidney, hearing, and thyroid problems.

• Psychological support and educational assistance: To address learning difficulties and social development.

Prognosis

With appropriate medical care and support, individuals with Turner syndrome can lead healthy, productive lives. Life expectancy may be slightly reduced due to the increased risk of cardiovascular complications, but early detection and ongoing management significantly improve outcomes. Regular follow-up with a multidisciplinary healthcare team is essential for addressing the wide range of possible medical and developmental challenges associated with the condition.