Shereshevsky-Turner syndrome: what is it, causes, symptoms, treatment

What is Shereshevsky-Turner syndrome?

Shereshevsky-Turner syndrome (also called Shereshevsky syndrome, Turner syndrome) is a rare chromosomal disorder that affects women. The disorder is characterized by partial or complete loss (monosomy) of one of the second sex chromosomes. Turner syndrome is a highly variable condition and can manifest itself differently in every woman.

Affected women can potentially develop a wide variety of symptoms that affect many different organ systems. Short stature and premature ovarian failure, which can lead to an inability to reach puberty, are common symptoms. Most women with Turner syndrome are infertile. Various additional symptoms may occur, including eye and ear abnormalities, skeletal malformations, heart disease and kidneys. Intelligence is generally normal, but affected individuals may have some learning disabilities.

Shereshevsky-Turner syndrome can be diagnosed before birth or shortly after birth or in early childhood. However, in some cases, this disorder can only be diagnosed in adulthood, often inadvertently. In most cases, this disease does not occur in families and occurs randomly for no apparent reason (sporadically).

Shereshevsky-Turner syndrome is one of the most common chromosomal disorders and probably the most common genetic disorder in women.

Symptoms and Signs

The symptoms and severity of Shereshevsky syndrome can vary from one person to another. Many signs of the disorder are nonspecific, while others may develop slowly or may be subtle. It is important to note that affected individuals may not have all of the symptoms described below. Affected families should talk to doctors about their specific case, associated symptoms, and overall prognosis.

Skin fold on the neck.

The anomaly is considered one of the most frequent manifestations of the syndrome (in 70% of cases). It looks like a pterygoid seal that runs from the back of the head to the trapezius muscles.

With a significant excess of skin, a visible membrane tightened between the head and shoulders appears. Such a cosmetic defect is corrected with a simple operation.

Small growth.

In newborns with a genetic disorder, body length varies between 42-45 cm. However, with the mosaic form of the syndrome, growth may be normal. Development is lagging behind in the female pattern.

Sometimes short stature is caused by a violation in the formation of the spinal column (fusion of the vertebrae or deformation).

"Face of the Sphinx".

The symptom can also occur with other diseases, however, with Shereshevsky-Turner syndrome, it is diagnosed in 35% of cases and is complemented by cervical skin pathology.

A person has thickened lips (see. photo), there are no natural folds in the forehead area ("polished forehead"). It is difficult for him to close his eyelids completely. Facial expressions are usually difficult (due to congenital weakness of the facial muscles).

A barrel-shaped or flattened rib cage.

In the first case, the frontal and anteroposterior chest dimensions are practically the same. Deformity occurs in 45% of anomalies.

With a defect in the formation of the bones of the chest, its flattening is noted.

With moderately pronounced pathologies of the development of the skeletal system, the symptom may be barely noticeable with age. The violation is not promptly corrected. Usually, this effect is not needed. The defect does not cause changes in the functioning of the heart or respiratory system.

Puffiness.

Edema is usually localized in the area of ​​the feet or lower leg and is considered a specific symptom (occurs with varying degrees of severity in more than 50% of patients). Nails look pinched. In the presence of congenital malformations, the swelling is very severe.

Poor weight gain.

The weight of newborn babies with Turner syndrome ranges from 2500-2800 g, within the normal range. But with the growing up of the baby, the body weight gain deviates from the optimal values. In the future, he will always be worse than his peers.

Abnormal development of the auricles.

The ears are usually located below eye level. The cartilage that forms the ears in people with Shereshevsky syndrome is often underdeveloped and can cause hearing loss.

Epicantus.

This is the name of the formation of a skin fold in the inner corner of the eye (see. Photo). In this case, a combination with a Mongoloid incision (as in children with Down syndrome) missing.

Hallux valgus.

Pathological curvature of the elbows, when the lowered arm is unable to straighten and deviates to the side of the body. It is observed in almost 65% of patients with the disease. A similar anomaly can be diagnosed in the knee joints, making it difficult to walk.

Finger deformities.

Deformities of the fingers (clinodactyly of the little finger, syndactyly) are diagnosed in 75% of cases. They are not always noticeable in infants, and are often detected as they grow older.

Abnormal position of the nipples.

An increased distance between the nipples on the chest is a typical sign of an anomaly only when combined with other manifestations of Turner syndrome. It is observed in 35% of patients with chromosomal abnormalities.

Hyperpigmentation of the skin.

The symptom is observed in 35% of cases of Shereshevsky-Turner pathology and is not considered specific. The accumulation of pigment can provoke endocrine disorders. Pathological formations appear in the form nevi, birthmarks.

Cardiovascular pathology.

The most common cardiovascular problems in Shereshevsky-Turner syndrome are patent ductus arteriosus, ventricular septal defect, coarctation or aortic aneurysm.

Heart defects associated with some cases of Turner syndrome can increase the risk of severe, life-threatening complications, including high blood pressure in the arteries of the lungs (pulmonary hypertension) or dissection of the aorta - a condition in which a rupture occurs in the inner wall of the aorta. Blood rushes into the middle layer of the aorta, with the result that the middle and inner layers are separated (stratified). Aortic dissection can rupture the outer wall of the aorta.

In some cases, you may experience kidney diseaseincluding horseshoe kidneys or absence (agenesis) of the kidneys. Renal abnormalities increase the risk urinary tract infections and high blood pressure (arterial hypertension).

Intelligence in women with Turner syndrome is usually normal. However, affected women may develop learning problems, especially difficulties with visual-spatial relationships. An example is right-to-left disorientation. Affected individuals may have difficulty learning math, non-verbal memory, and attention. Affected women may also have difficulty in certain social situations.

Some people with Turner syndrome are at high risk of developing certain disorders, including Hashimoto's thyroiditis, inflammatory diseases of the colon, hypothyroidism, vitiligo, osteoporosis, baldness, hypertrichosis, diabetes, celiac disease, obesity, coronary heart disease. The risk of developing colon cancer.

Causes

Shereshevsky-Turner syndrome is caused by partial or complete loss (monosomy) of the second sex chromosome. Chromosomes are found in the nucleus of all cells in the body. They carry the genetic characteristics of each person and come in pairs. We receive one copy from each parent. Chromosomes are numbered 1 through 22; The 23rd pair usually consists of one X and one Y chromosome for males and two X chromosomes for females. Thus, women with a normal chromosomal structure (karyotype) have 46 chromosomes, including two X chromosomes (46, XX karyotype). Each chromosome has a short arm labeled "P", and a long shoulder, indicated "Q". The chromosomes are further subdivided into many numbered bands.

In women with Turner syndrome, all or part of the second sex chromosome is missing. The reason why this happens is unknown and is believed to be the result of a random event. In some cases, the chromosomal abnormality appears to arise spontaneously due to an error in the division of the parent's reproductive cells, either in the father's sperm or in the mother's egg. This leads to the fact that the genetic error appears in all cells of the body.

In many cases, only a certain percentage of a person's cells can be affected. It is called mosaicism. In particular, some cells have normal 46 chromosomes (one cell line), while other cells do not have normal 46 chromosomes (second cell line). This second cell line can contain various abnormalities such as partial or complete loss of the X chromosome. In these cases, the loss of genetic material from the X chromosome usually occurs due to spontaneous errors very early in the development of the fetus. In theory, in people with mosaicism, Shereshevsky-Turner syndrome can cause fewer developmental problems than in other cases because fewer cells are affected. However, this is difficult to predict.

In some cases, more rare chromosomal abnormalities (other than full or partial monosomy) can cause the syndrome. Such abnormalities include the ring chromosome or isochromosome X. Ring chromosomes arise when the ends of a chromosome break off and the long and short arms join together to form a ring. Isochromosomes occur when one part of a chromosome is missing and replaced with an identical version of another branch.

In rare cases, some cells have one copy of the X chromosome, while other cells have one copy of the X chromosome and some material from the Y chromosome. The amount of Y chromosome material is not enough to cause the development of any male characteristics, but is associated with an increased risk of developing a form of cancer known as gonadoblastoma.

Most of the symptoms of Shereshevsky-Turner syndrome arise from the loss of specific genetic material from one of the X chromosomes. Until now, it is known that one gene, SHOX plays a role in the development of the syndrome. Gene SHOX encodes a protein that helps regulate other genes in the body. Protein gene product SHOX plays a role in the growth and maturation of the skeleton. Researchers believe that the loss of one gene SHOX in the altered X chromosome is the main cause of low growth in women with Shereshevsky-Turner syndrome.

Affected populations

Shereshevsky syndrome affects about 1 woman in 2,000 to 2,500 live births. There are no known racial or ethnic factors that influence the incidence of the disorder. In some cases, the disorder is diagnosed before birth or shortly after birth. However, mild cases may go undetected until late in life and even into adulthood.

Diagnostics

During pregnancy, the syndrome can be suspected during an ultrasound examination (ultrasound). With Shereshevsky-Turner syndrome, some physical abnormalities appear:

• thickening of the collar zone;
• cervical hygroma;
• expansion of the renal pelvis and calyces;
• deformation of bones, shape of the head, limbs;
• heart defects;
• lack of water or polyhydramnios.

Thickening of the collar space and hygroma are already noticeable at the first planned ultrasound. With a mosaic type of pathology, the results of ultrasound diagnostics remain normal.

To clarify the form of the disorder, fetal karyotyping is recommended. The study is carried out from 10 to 12 weeks of pregnancy.

When performing this procedure (under ultrasound control) with a special needle (inserted into the uterine cavity through the anterior abdominal wall) or a catheter (through cervix), amniotic fluid (amniocentesis), blood from the umbilical cord vessels (cordocentesis) or a fetal cell sample (biopsy chorion).

Treatment

Treatment of Shereshevsky-Turner syndrome is aimed at specific symptoms that appear in each person. Treatment may require the coordinated efforts of a team of specialists. Pediatricians, pediatric specialists, surgeons, cardiologists, endocrinologists, speech therapists, otolaryngologists, ophthalmologists, psychologists and other health care providers may need systematic and comprehensive planning for affective treatment child. Genetic counseling is recommended for affected individuals and their families.

Specific therapeutic procedures and interventions can vary depending on many factors, such as the severity of the disease; the presence or absence of certain symptoms; the person's age and general health. Decisions regarding the use of specific drug regimens and / or other treatments must be made physicians and other members of the healthcare team in careful consultation with the patient based on characteristics case; carefully discussing the potential benefits and risks, including possible side effects and long-term consequences; patient preferences; and other relevant factors.

There is no cure for Shereshevsky's syndrome, but treatments have been developed that can improve physical development. With proper medical care, women with Turner syndrome should be able to lead full, productive lives. The main methods of treating sick people are growth hormone and estrogen therapy.

Individuals with Shereshevsky-Turner syndrome may benefit from growth hormone (GH) therapy, which can help normalize growth. The Food and Drug Administration (FDA) has approved the use of recombinant growth hormone for the treatment of children with Turner syndrome. Recombinant GR is artificially created in the laboratory. The best age to start GH therapy and the optimal duration of therapy in women with the syndrome are unknown. As a general rule, the sooner GH therapy is started, the more beneficial it is for those affected. However, there are many individual factors that ultimately determine the effectiveness of growth hormone therapy. Decisions regarding GH therapy in individuals with Shereshevsky syndrome are best made after consultation with a pediatric endocrinologist.

Most women with Shereshevsky-Turner syndrome require sex hormone replacement therapy to get through the normal development associated with puberty and begin their menstrual period. Replacement therapy using estrogen and progesterone usually promotes puberty and the development of secondary sex characteristics. Replacement therapy with these hormones is usually started around 12-14 years of age. It is during this time that most average girls enter puberty.

Most women with Turner syndrome remain unable to conceive. Sometimes in vitro fertilization (IVF) with a donor egg and implanted pregnancy is possible. In most cases, these pregnancies are risky and require close consultation with your doctor.

Additional treatment is symptomatic and supportive. For example, hormone replacement therapy can be used to treat people with thyroid problems. Correcting hearing loss with hearing aids is another important intervention that can help with learning and social interaction.

Early intervention is essential for children with the syndrome to reach their potential. Special services that may be helpful to affected children may include special psychosocial support, speech therapy, and other similar services.

Forecast

The prognosis for Turner syndrome is favorable in terms of life expectancy and intellectual development. The exceptions are cases of occurrence:

• congenital heart defects;
• spina bifida;
• abnormal formation of the genitourinary system.

With regard to the restoration of fertility, mostly patients remain infertile. However, with adequate and timely therapy, women can create families, lead a full sex life, and give birth to children.

Shereshevsky-Turner syndrome is a complex genetic pathology that affects the entire body. However, with timely diagnosis and correctly performed treatment, patients have a chance to adapt in society.