Turner’s syndrome


Syndrome includes: congenital lymphedema, gonadal dysgenesis and short stature.

Turner syndrome (TS), also known 45,X.

A genetic condition in which a female is partly or completely missing an X chromosome.

While most people have 46 chromosomes, people with TS usually have 45.

Turner syndrome is caused by the absence of one complete or partial copy of the X chromosome in some or all the cells.

The abnormal cells may have only one X (45,X) or they may be affected by one of several types of partial monosomy like a deletion of the short p arm of one X chromosome (46,X,del(Xp)) or the presence of an isochromosome with two q arms.

Overall, the functional X chromosome usually comes from the mother.

In most cases, Turner syndrome is a sporadic event.

The risk of recurrence is not increased for subsequent pregnancies.

TS may be diagnosed by amniocentesis or chorionic villus sampling during pregnancy, and can be identified by abnormal ultrasound findings.

Such abnormal US findings include: heart defect, kidney abnormalities, cystic hygroma, and ascites.

US studies found 67.2% of prenatally diagnosed cases of Turner syndrome were detected by abnormalities on ultrasound, 69.1% of cases had one anomaly present, and 30.9% had two or more anomalies.

TS patients may experience adverse psychosocial outcomes which can be improved through early intervention and the provision of appropriate psychological and psychiatric care.

There is a possible association between age at diagnosis and increased substance use and depressive symptoms.

Women with Turner syndrome are almost universally infertile.

Estrogen replacement therapy is used to initiate growth of secondary sexual characteristics at the time when puberty should onset.

Growth hormone increases growth and adult height.

Reproductive technologies have also been used to help women with Turner syndrome become pregnant.

99% of Turner syndrome pregnancies spontaneously abort in the first trimester, and account for 10% of of all spontaneous abortions.

In mosaic cases of Turner syndrome that contains Y-chromosome (e.g. 45,X/46,XY) oophorectomy is recommended because of risk of ovarian cancer.

TS is characterized by primary amenorrhoea, premature ovarian failure, streak gonads and infertility, and failure to develop secondary sex characteristics.

Incidence 1:2500-1:3000 live-born females.

With TS with mosaicism, the symptoms are usually fewer and possibly none.

Diagnosis is based on physical signs and genetic testing.

An increased risk of Turner syndrome may be associated by abnormal triple or quadruple maternal serum screen.

Turner syndrome can be diagnosed after birth at any age.

Diagnosis at birth is made by due to heart problems, an unusually wide neck or swelling of the hands and feet.

It is common for diagnosis to be delayed for several years, often until the girl reaches the age of puberty and fails to develop typically.

In childhood, a short stature can be indicative of Turner syndrome.

Karyotype analysis, analyzes the chromosomal composition of the individual, and is the test of choice to diagnose Turner syndrome.

Common findings and symptoms of Turner syndrome, include:

Short stature

Lymphedema of the hands and feet of a newborn

Broad chest and widely spaced nipples

Low posterior hairline

Low-set ears

Reproductive sterility

Rudimentary ovaries gonadal streak

Underdeveloped gonadal structures that later become fibrotic.


Increased weight, obesity

Shortened metacarpal IV

Small fingernails

Characteristic facial features

Webbed neck from cystic hygroma in infancy

Aortic valve stenosis

Coarctation of the aorta

Bicuspid aortic valve

Horseshoe kidney

Visual impairments

Ear infections and hearing loss

High waist-to-hip ratio as the hips are not much bigger than the waist

Attention deficit hyperactivity disorder

Nonverbal learning disability

Cardiovascular malformations among patients with Turner syndrome ranges from 17% to 45%.

Bicuspid aortic valve abnormalities and coarctation of the aorta, the two most common cardiovascular malformations.

Partial anomalous venous drainage and aortic valve stenosis or aortic regurgitation, are also more common than in the general population.

Up to 15% of adults with Turner syndrome have bicuspid aortic valves,.

Bicuspid valves are more likely to deteriorate and later fail.

Calcification also occurs in the valves, which may lead to aortic stenosis or regurgitation.

Between 5% and 10% of Turner syndrome patients have coarctation of the aorta.

The presence of a coarctation of the aorta in a female is suggestive of Turner syndrome and indicates the need for further tests, such as a karyotype.

It is associated with unusual forms of partial anomalous venous drainage.

The left-sided cardiovascular malformations can result in an increased susceptibility to bacterial endocarditis, and prophylactic antibiotics should be considered.

It is often associated with hypertension, sometimes starting as early as childhood.

Hypertension is mostly idiopathic or may be associated with cardiovascular, kidney abnormalities, or coarctation of the aorta.

Aortic dissection occurs 1 to 2% of patients with Turner, and surveillance is highly recommended.

Hypertension risk is increased threefold in patients with turner syndrome.

Additional findings may include: miicrognathia, cubitus valgus, soft upturned nails, palmar crease, and drooping eyelids, pigmented moles, hearing loss, and a high-arch palate.

The risk of auto immune disease is approximately twice as high as the risk in the general female population.

The incidence of celiac disease among patients with the Turner syndrome is increased by a factor of 11.

The fourth metacarpal bone of the fourth toe and ring finger may be unusually short, as may the fifth.

Turner syndrome manifests itself differently in each patient.

No cure is known.

All regions of the world are affected about equally.

Associated with a shorter life expectancy, mostly due to heart problems and diabetes.

Turner syndrome patients have normal intelligence, and demonstrate relative strengths in verbal skills.

They may exhibit weaker nonverbal skills in arithmetic, visuospatial skills, and processing speed.

In most cases Turner syndrome patients are employed as adults and lead productive lives, as problems do not interfere with daily activities of living.

The “Ring-X Turner syndrome” accounts for around 2–4% of all Turner syndrome cases, and has about a 60% association with intellectual disability.

Treatment with human growth hormone may increase adult height, estrogen replacement therapy can promote development of the breasts and hips..

Medical care may be required to manage other health problems with which TS is associated.

Most of the physical findings are harmless.

Growth hormone can increase height significantly and perhaps normalize it.

The average height of a woman with Turner syndrome, is 4 ft 7 in the absence of hormonal treatment.

Osteoporosis can decrease height, exacerbate the curvature of the spine, possibly leading to scoliosis, and is associated with an increased risk of bone fractures.

One-third of all women with Turner syndrome have kidney abnormalities: including single, horseshoe-shaped kidney on one side of the body, abnormal urine-collecting system, and poor blood flow to the kidneys

The kidneys of most women with Turner syndrome function normally.

Patients with Turner’s mosaicism, however, can reach normal average height.

Osteoporosis develops commonly in TS due to inadequate production of estrogen.

Characterized by estrogen deficiency due to nonfunctioning bilateral streaks of gonadal fibrous stroma.

Hormone replacement therapy is beneficial and not associated with an increased incidence of breast cancer.

Patients are often short and webbed neck, low-set ears, have a low hairline at the back of the neck.

Have associated heart defects, diabetes, and low thyroid hormone more frequently than the general population.

Patients with Turner syndrome are at a moderately increased risk of developing type 1 diabetes in childhood and a substantially increased risk of developing type 2 diabetes by adult years.

Approximately one-third of all women with Turner syndrome have a thyroid disorder, usually it is hypothyroidism.

Hypothyroidism is specifically due to Hashimoto’s thyroiditis.

Significant medical problems can be associated with the syndrome are treatable with surgery and medication.

99% of Turner syndrome conceptions are thought to end in miscarriage or stillbirth.

As many as 15% of all spontaneous abortions have the 45,X karyotype.

Most people with the syndrome have normal intelligence.

Associated with a shorter life expectancy

It is not usually inherited from a person’s parents.

No environmental risks are known.

Maternal age does not play a role.

When the chromosomal abnormality is present in some cells, it is known as TS with mosaicism.

Many patients have impaired spatial visualization.

While it is not associated with intellectual disability or impaired cognition, learning difficulties are common among women, particularly a specific difficulty in perceiving spatial relationships, such as nonverbal learning disorder.

Individuals may manifest difficulties with motor control or with mathematics.

Vision and hearing problems occur more often.

The short stature, and swollen hands and feet are seen at birth.

Menstrual periods and breasts manifest only with hormone treatment.

They are unable to have children without reproductive technology.

Fertility technology provides the opportunity of pregnancy in these patients.

There is an increased risk for aortic dissection in pregnancy.

Mosaicism is estimated to be relatively common in affected individuals (67–90%).

In the majority of cases where monosomy occurs, the X chromosome comes from the mother.

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