Monosomy is what?

The genetic structure of a person is determined by 23 pairs of chromosomes, which differ in shape and size. The largest chromosome 1. It is over the size of the chromosome 22 almost 4 times. 23 pair are the chromosomes X and Y. They determine the sex of people. In women 23 the pair contains 2 chromosomes X, this pair is designated XX. In men, 23 pairs consist of their chromosomes X and Y, i.e. Is a pair of XY.

When the embryo is formed in the uterus of the future mother, he does not yet have any signs of a person, but 23 pairs of chromosomes already determine the sex of the future baby. The previous 22 pairs are called autosomes. They ensure the development of all internal organs and tissues of the baby.

Infertility as one of the signs of monosomy

Female infertility can be the result of various pathologies. In the case of a disruption in the structure of the 23 pairs of chromosomes, it is laid even before birth, when the potential mother herself was in a state of embryo in the womb of the mother.

If there is no X chromosome in pair XX or it is damaged, such a pathology is called X monosomy. Infertility is one of the most revealing signs of X monosomy. Modern medicine studies both the signs of this pathology and the ways of its treatment.

What it is?

Monosomy is a deviation, named after the scientist who discovered him, Turner's syndrome. This genetic disease occurs only in girls. According to statistics, it is found in about 1 out of 2,500 cases.

At the moment, the development of medicine to prevent Turner syndrome is impossible. Girls with this pathology can lead a normal life, but they need a doctor's observation, as complications can develop.

Other signs of monosomy

It was revealed that girls with the probability of having a syndrome of monosomy even in childhood may have the following signs of the disease:

• In infancy, the hands and feet are swollen.
• Kids are lagging behind their peers in growth.
• The palate of these girls is higher than that of the average child, and the ears are lower.
• Sick girls are prone to gaining excessive weight.
• Flat feet are often observed.
• Eyelids hang low over the eyes.
• Strabismus.
• The neck is shortened.
• Observation of hairy body parts.
• Shortened hands.

In addition to these diseases, a teenage girl can be identified:

• Heart disease (inconsistency of valve walls).
• The slowing of the onset of puberty.
• Hearing problems.
• Frequent increase in blood pressure (hypertension).
• Constant diseases associated with infections in the ears.
• Dryness in the eyes.
• Violation of posture, up to scoliosis.

From the point of view of sexual development, one observes:

• Disproportion of the external genitalia.
• Underdevelopment of mammary glands.
• Absence of hair under armpits and above the pubis.
• Underdevelopment of the uterus.
• Absence or passivity of the ovaries.
• Low content of female hormones.
• Menstrual passivity, up to the absence of menstruation.

The difficulty in diagnosing symptoms is that the same signs can be observed in other diseases. If they are in a girl of any age, it is necessary to have a checkup in a polyclinic.

One of the characteristic features of monosomy on sex chromosomes is the excess skin on the sides of the neck, which forms longitudinal folds.

The causes of the appearance of monosomy

At this stage of the development of science, it was not possible to establish in detail the causes of the appearance of monosomy in the fetus. What is known for certain - pathology is not related to heredity. The main influence on the occurrence of pathology in the fetus is the gene disorders of the germ cells of the father during the period of conception. This is the main reason for monosomy.

If the father's genes underwent a mutation, the structure of the X chromosome underwent a rearrangement, and a pair of chromosomes could also be damaged in a child-girl. But it should be noted that in such a family it is not worthwhile to put a cross on the birth of children. At the father with infringement of an X-chromosome it is very probable conception and a birth of quite healthy child.

Why does X chromosome monosomy appear? The causes of this disease are being studied, but at this stage medicine can say:

• The appearance of monosomy in the fetus is not associated with unfavorable external conditions.
• This pathology is not inherited. Otherwise, it would receive all the girls in the family of a genetically injured father.
• The most likely cause of Turner's syndrome is the influence of harmful factors on the sex cells of the father shortly before conception.
• During the period of division of the zygote and its transformation into an embryo, failures can occur, which are the cause of the mosaic type of monosomy.

Diagnosis of the disease

To the monosomy of the chromosome in the fetus was excluded, even before the birth of a group of women at risk make a special genetic examination. This examination - prenatal genetic analysis - includes ultrasound examination, biopsy of muscles and fetal skin, a laboratory blood test.

Such serious examinations the doctor appoints when it comes to whether to leave the fetus or terminate the pregnancy. Therefore, they are appointed in the first 3 months of pregnancy. That is, if the family does not decide whether to be or not to be a child, surveys are not scheduled.

A physician can recommend a genetic examination so that 21 chromosome monosomy is excluded if:

• The future mother is over 35 years old.
• In the family of a pregnant woman, hereditary pathologies were observed.
• In the family, fragile (fragile) X chromosomes were observed.
• Suspicion of hemoglobinopathy.
• Suspicion of Down's syndrome in the child and other related to heredity, adverse situations.

When diagnosing such moments are taken into account that the examination should not cause harm to the health of the mother or the child, it can not lead to loss of the fetus. Doctors conducting diagnostics are required to have high qualification for diagnosis based on the results of the survey.

Before a genetic examination, a woman should undergo a screening test at a gynecologist in her clinic, so that the doctor decides whether the pregnant woman is at risk, ie, is there a chance that the fetus will show a monosomy syndrome. Only after a positive answer to this question the pregnant woman is sent for a genetic examination.

In prenatal diagnosis, there are other methods - a puncture of the bladder with the purpose of taking amniotic fluid for analysis, taking blood from the umbilical cord, and fetoscopy. The latter is the introduction of the probe and the examination of the fetus through it. Fetoscopy is used very rarely, because at the modern level of medical equipment development this procedure is successfully replaced by ultrasound.

If the fetus did not detect monosomy on the X chromosome in time, and a suspicion of a diagnosis appeared several years after birth, the girl is examined in the following ways:

• The absence of sexual chromatin is determined.
• The karyotype is determined.
• Consultation of a children's gynecologist is being conducted.
• They make ultrasound of internal genital organs.
• At the age of 9-10 years, a blood test for hormones is performed.
• An x-ray of brushes is assigned to the correspondence of bone development to the age norm.

According to the results of the survey, a special commission may decide on disability.

Types of monosomy

Monosomy is a disease that happens of different types. A girl born in the second chromosome in pair XX may be absent altogether. This type of genetics is designated as 45X0. These girls are completely absent or undeveloped ovaries and uterus. Their puberty will not take place. There is no chromosome, which determines the development of secondary sexual characteristics, the sex organs themselves and the corresponding hormones.

If the second chromosome in pair XX is present, genetic type 46 XY. In this case, the girl will have a uterus and ovaries, but they will have a rudimentary structure, i.e., she will not be able to ovulate and conceive a child.

Much more dangerous is the case when one chromosome is missing in pairs 1 to 22. They are called autosomes. With the normal development of the zygote in each cell, the two chromosomes are sent to its different poles. If one autosome is not enough, only the existing chromosome is sent to the cell pole. When it merges with a healthy one, the zygote is obtained with an abnormal amount of chromosomes. This leads to the death of the fetus and the spontaneous termination of pregnancy. If the number of chromosomes is greater by 1 than in the standard version, a miscarriage may not occur, but then a child is born, unable to live long.

Partial monosomy

Partial monosomy is formed during the breakdown of the chromosome, as a result of which one whole and part of the second chromosome remains in the pair. The cause of the pathology is the structural chromosome rearrangement of the parental cells of the parents in the period shortly before conception. The consequences of the disease depend on which particular chromosome underwent partial destruction.

Catching scream syndrome

The destruction of a part of the chromosome in the 5th pair creates a "cat scream" syndrome. The larynx of a sick child is narrowed, the cartilages are soft, as a result, the baby's crying resembles a cat's meow.

For this type is also characteristic of the muscle lethargy of the baby, the lunar face, mental underdevelopment and physical lag in comparison with their peers. The child has underdevelopment of the skull, low ears, strabismus and vision problems. As a rule, such children suffer from heart defects. These patients do not last long - the term reaches no more than 10 years. A similar pathology is seen in 1 of 45 000 cases.

Wolff-Hirschhorn Syndrome

The rupture of one chromosome from 4 pairs (Wolff-Hirschhorn syndrome) occurs in 1 case out of 100,000. Children who have monosomal chromosomes of 4 pairs are more likely to develop in young mothers and fathers. The weight of the baby at birth is significantly less than the norm - about 2 kg. Infants are delayed physical and mental development, motor skills is complicated very slowly. They suffer from the development of the skull.

On external grounds, you can note the beak-like nose, protruding forehead, low ears, longitudinal folds in front of the ears. They also have muscular lethargy. They almost do not react to external stimuli. Such children are susceptible to convulsions. Outwardly, they may have an abnormal eye structure, a small mouth with lowered lips in the corners, a curvature of the feet. Sick children often suffer from heart defects. Affected kidney diseases. Most of the children with this chromosomal destruction do not survive to a year.

Orbeli Syndrome

Rupture of the chromosome from 13 pairs is called the Orbeli syndrome. Children with this deviation are born with a low weight - up to 2.2 kg. Have pathologies of almost all internal organs. They have an underdeveloped skull, there is no nose bridge - the forehead immediately passes into the nose. The nose has an enlarged width, the sky is high, the ears are underestimated. The baby has visual abnormalities, underdevelopment of the musculoskeletal system. There may be no natural canal of the rectum and anus. Often observed heart disease, kidney disease, brain pathology. These children, as a rule, are oligophrenic, they are tormented by convulsions, they often lose consciousness. Infants do not live up to 1 year.

Monosomy is a very dangerous disease, and children with partial monosomy are extremely rare. Future mothers do not need to be adjusted to such a sad event.

Complications of monosomy X

Women with monosomy X are susceptible to various diseases of the internal organs more often than genetically healthy people. They should be observed at the doctor and periodically undergo medical examination.

A common complication is renal pathology. In sick women, infectious diseases of the urogenital organs often occur, the kidneys are not properly located, and the kidneys are not fully developed.

If the monosomy of a person has a place, then sometimes the thyroid gland suffers, in which insufficient level of hormones necessary for the body is produced. The thyroid gland inflames, because of what these troubles occur. Treatment can only serve as a medication that supports a normal hormonal background. They should be appointed by a doctor. Self-medication is unacceptable.

Those suffering from Turner's syndrome are prone to celiac disease. This pathology is expressed in the occurrence of allergies to gluten protein. Patients can not eat products from wheat and barley.

Complications can give any monosomy. Diseases that accompany monosomy may be different, for example, cardiovascular diseases. Women with pathology should be monitored by a cardiologist who will monitor the condition of their aorta and prevent the development of hypertension.

Since patients with Turner syndrome are prone to obesity, they may face diabetes.

Frozen pregnancy

Genetic pathologies, including fetal monosome, are considered one of the reasons for the development of a frozen pregnancy. This is the death of the fetus inside the womb of the mother. With monosomy, this happens before the 12th week of pregnancy. Sometimes the life of the fetus is longer - up to 20 weeks. Such a danger threatens if the fetus lacks one of the chromosomes from pairs 1-22, this is the so-called trisomy. Monosomy is the reason for a deliberate termination of pregnancy.

Trying to keep the fruit with serious developmental anomalies does not seem to be meaningful. Frozen pregnancy results in miscarriage. This risk affects women over the age of 35 - 40 years, as well as those who have had it before.

Scientists also noted a decrease in the lifespan of women with monosomy, a tendency to atherosclerosis, tumors.

Treatment of monosomy

Monosomy is a pathology that does not respond to treatment, but doctors successfully cope with its consequences. The essence of the treatment is that the organism lacking hormonal regulation of the ovaries needs artificial regulation. The pathology of internal organs is treated medically or surgically. Complex treatment includes:

• Admission of drugs of growth hormones to girls immediately after diagnosis.
• By the age of sexual maturation of healthy children suffering from monosomy, sexual hormones are prescribed.
• Those who want to endure a child with women with pathology are assisted by reproductive medicine-the introduction of a donor fertilized egg with further monitoring of the course of pregnancy.
• Treatment of pathologies of internal organs with modern preparations and procedures.
• Psychological assistance to women with a view to their adaptation in a social environment, taking into account the characteristics of physiology.

The most important point in treatment is its timely onset - immediately after diagnosis. The second point is the consideration of the form of monosomy. If her type is 45X0, then a woman can not have her child by any means. Psychological help should prepare her for thinking about the adoption of an orphan.

The mosaic form of monosomy X - 46XY with the modern development of medicine makes it possible to bear your child. But he can be born sick. Adoption is also preferable in this variant.