Hereditary diseases in children. Genetic diseases that are inherited

At the beginning of the 21st century, there are already more than 6 thousand types of hereditary diseases. Now in many institutes of the world a person is being studied, the list of which is huge.

The male population has more and more genetic defects and less and less chance of conceiving a healthy child. While all the reasons for the patterns of development of defects are unclear, however, it can be assumed that in the next 100-200 years science will cope with the solution of these issues.

What are genetic diseases? Classification

Genetics as a science began its research path in 1900. Genetic diseases are those that are associated with abnormalities in the human gene structure. Deviations can occur both in 1 gene and in several.

Hereditary diseases:

1. Autosomal dominant.
2. Autosomal recessive.
3. Hooked to the floor.
4. Chromosomal diseases.

The probability of an autosomal dominant deviation is 50%. With autosomal recessive - 25%. Sex-linked diseases are those caused by a damaged X chromosome.

hereditary diseases

Here are some examples of diseases, according to the above classification. So, dominant-recessive diseases include:

• Marfan syndrome.
• Paroxysmal myoplegia.
• Thalassemia.
• Otosclerosis.

Recessive:

• Phenylketonuria.
• Ichthyosis.
• Other.

Sex-linked diseases:

• Hemophilia.
• Muscular dystrophy.
• Farby disease.

Also on hearing human chromosomal hereditary diseases. The list of chromosomal abnormalities is as follows:

• Shereshevsky-Turner syndrome.
• Down Syndrome.

Polygenic diseases include:

• Dislocation of the hip (congenital).
• Heart defects.
• Schizophrenia.
• Cleft lip and palate.

The most common gene anomaly is syndactyly. That is, the fusion of fingers. Syndactyly is the most innocuous disorder and is treated with surgery. However, this deviation accompanies other more serious syndromes.

What diseases are the most dangerous

Of those listed diseases, the most dangerous hereditary human diseases can be distinguished. Their list consists of those types of anomalies where trisomy or polysomy occurs in the chromosome set, that is, when the presence of 3, 4, 5 or more is observed instead of a pair of chromosomes. There is also 1 chromosome instead of 2. All these deviations occur due to a violation of cell division.

The most dangerous human hereditary diseases:

• Edwards Syndrome.
• Spinal muscular amyotrophy.
• Patau syndrome.
• Hemophilia.
• Other diseases.

As a result of such violations, the child lives for a year or two. In some cases, the deviations are not so serious, and the child can live up to 7, 8 or even 14 years.

Down syndrome

Down syndrome is inherited if one or both parents are carriers of defective chromosomes. More specifically, the syndrome is linked to a chromosome (i.e., chromosome 21 is 3, not 2). Children with Down syndrome have strabismus, wrinkling of the neck, abnormally shaped ears, heart problems, and mental retardation. But for the life of newborns, a chromosomal anomaly does not pose a danger.

Now statistics say that out of 700-800 children, 1 is born with this syndrome. Women who want to have a baby after 35 are more likely to have such a baby. The probability is somewhere around 1 in 375. But a woman who decides to have a baby at 45 has a probability of 1 in 30.

acrocraniodysphalangia

The type of inheritance of the anomaly is autosomal dominant. The cause of the syndrome is a violation in chromosome 10. In science, this disease is called acrocraniodysphalangia, if it is simpler, then Apert's syndrome. It is characterized by such structural features of the body as:

• brachycephaly (violations of the ratio of the width and length of the skull);
• fusion of the coronal sutures of the skull, as a result of which hypertension is observed (increased blood pressure inside the skull);
• syndactyly;
• convex forehead;
• often mental retardation against the background of the fact that the skull squeezes the brain and does not allow nerve cells to grow.

Nowadays, children with Apert syndrome are given skull augmentation surgery to restore their blood pressure. And mental underdevelopment is treated with stimulants.

If there is a child in the family who has been diagnosed with the syndrome, the likelihood that a second child will be born with the same abnormality is very high.

Happy Doll Syndrome and Canavan-Van Bogart-Bertrand Disease

Let's take a closer look at these diseases. You can recognize Engelman's syndrome somewhere from 3-7 years. Children have cramps, poor digestion, problems with coordination of movements. Most of them have strabismus and problems with the muscles of the face, because of which the smile is very often on the face. The movements of the child are very constrained. For doctors, this is understandable when a child tries to walk. Parents in most cases do not know what is happening and even more so with what it is connected. A little later, it is also noticeable that they cannot speak, they only try to mutter something inarticulately.

The reason why a child develops a syndrome is a problem in the 15th chromosome. The disease is extremely rare - 1 case per 15 thousand births.

Another disease - Canavan's disease - is characterized by the fact that the child has a weak muscle tone, he has problems with swallowing food. The disease is caused by damage to the central nervous system. The reason is the defeat of one gene on the 17th chromosome. As a result, the nerve cells of the brain are destroyed with progressive speed.

Signs of the disease can be seen at 3 months of age. Canavan disease manifests itself as follows:

1. Macrocephaly.
2. Seizures appear at the age of one month.
3. The child is unable to hold his head upright.
4. After 3 months, tendon reflexes increase.
5. Many children go blind by the age of 2.

As you can see, human hereditary diseases are very diverse. This list is for example only and is far from complete.

I would like to note that if both parents have a violation in 1 and the same gene, then the chances of giving birth to a sick child are high, but if there are anomalies in different genes, then there is no need to be afraid. It is known that in 60% of cases, chromosomal abnormalities in the fetus lead to miscarriage. But still 40% of such children are born and fight for their lives.

Today, gynecologists advise all women to plan their pregnancy. After all, in this way many hereditary diseases can be avoided. This is possible with a thorough medical examination of both spouses. There are two points in the question of hereditary diseases. The first is a genetic predisposition to certain diseases, which manifests itself already with the maturation of the child. So, for example, diabetes mellitus, which one of the parents suffers from, can manifest itself in children in adolescence, and hypertension - after 30 years. The second point is directly genetic diseases with which the child is born. They will be discussed today.

The most common genetic diseases in children: description

The most common hereditary disease of a baby is Down syndrome. It occurs in 1 case out of 700. A neonatologist makes a diagnosis in a child while the newborn is in the hospital. In Down's disease, the children's karyotype contains 47 chromosomes, that is, an extra chromosome is the cause of the disease. You should know that girls and boys are equally susceptible to this chromosomal pathology. Visually, these are children with a specific facial expression, lagging behind in mental development.

Shereshevsky-Turner disease is more common in girls. And the symptoms of the disease appear at the age of 10-12: patients are not tall, the hair on the back of the head is low-set, and at 13-14 they do not have puberty and there are no periods. In these children, there is a slight lag in mental development. The leading symptom of this hereditary disease in an adult woman is infertility. The karyotype for this disease is 45 chromosomes, that is, one chromosome is missing. The prevalence of Shereshevsky-Turner disease is 1 case per 3000. And among girls up to 145 centimeters tall, it is 73 cases per 1000.

Only males have Klinefelter's disease. This diagnosis is established at the age of 16-18 years. Signs of the disease - high growth (190 centimeters and even higher), slight mental retardation, disproportionately long arms. The karyotype in this case is 47 chromosomes. A characteristic sign for an adult male is infertility. Kleinfelter's disease occurs in 1 in 18,000 cases.

Manifestations of a fairly well-known disease - hemophilia - are usually observed in boys after one year of life. Mostly representatives of the strong half of humanity suffer from pathology. Their mothers are only carriers of the mutation. Blood clotting disorder is the main symptom of hemophilia. Often this leads to the development of severe joint damage, such as hemorrhagic arthritis. With hemophilia, as a result of any injury with a cut in the skin, bleeding begins, which for a man can be fatal.

Another severe hereditary disease is cystic fibrosis. Usually, children under one and a half years old need to be diagnosed to identify this disease. Its symptoms are chronic inflammation of the lungs with dyspeptic symptoms in the form of diarrhea, followed by constipation with nausea. The frequency of the disease is 1 case per 2500.

Rare hereditary diseases in children

There are also genetic diseases that many of us have not heard of. One of them appears at the age of 5 years and is called Duchenne muscular dystrophy.

The carrier of the mutation is the mother. The main symptom of the disease is the replacement of skeletal striated muscles with connective tissue that is incapable of contraction. In the future, such a child will face complete immobility and death in the second decade of life. To date, there is no effective therapy for Duchenne myodystrophy, despite many years of research and the use of genetic engineering.

Another rare genetic disease is osteogenesis imperfecta. This is a genetic pathology of the musculoskeletal system, which is characterized by deformation of the bones. Osteogenesis is characterized by a decrease in bone mass and their increased fragility. There is an assumption that the cause of this pathology lies in a congenital disorder of collagen metabolism.

Progeria is a rather rare genetic defect, which is expressed in premature aging of the body. There are 52 cases of progeria in the world. Up to six months, children are no different from their peers. Further, their skin begins to wrinkle. Symptoms of senility appear in the body. Children with progeria usually do not live beyond the age of 15. The disease is caused by gene mutations.

Ichthyosis is a hereditary skin disease that occurs as a dermatosis. Ichthyosis is characterized by a violation of keratinization and is manifested by scales on the skin. The cause of ichthyosis is also a gene mutation. The disease occurs in one case in several tens of thousands.

Cystinosis is a disease that can turn a person into stone. The human body accumulates too much cystine (an amino acid). This substance turns into crystals, causing hardening of all body cells. The man gradually turns into a statue. Usually such patients do not live up to 16 years. The peculiarity of the disease is that the brain remains intact.

Cataplexy is a disease that has strange symptoms. At the slightest stress, nervousness, nervous tension, all the muscles of the body suddenly relax - and the person loses consciousness. All his experiences end in fainting.

Another strange and rare disease is extrapyramidal system syndrome. The second name of the disease is the dance of St. Vitus. Her attacks overtake a person suddenly: his limbs and facial muscles twitch. Developing, the syndrome of the extrapyramidal system causes changes in the psyche, weakens the mind. This disease is incurable.

Acromegaly has another name - gigantism. The disease is characterized by a high growth of a person. And the disease is caused by excessive production of somatotropin growth hormone. The patient always suffers from headaches, drowsiness. Acromegaly today also has no effective treatment.

All these genetic diseases are difficult to treat, and more often they are completely incurable.

How to identify a genetic disease in a child

The level of today's medicine makes it possible to prevent genetic pathologies. To do this, pregnant women are encouraged to undergo a set of studies to determine heredity and possible risks. In simple words, genetic analyzes are done to identify the propensity of the unborn baby to hereditary diseases. Unfortunately, statistics record an increasing number of genetic abnormalities in newborns. And practice shows that most genetic diseases can be avoided by curing them before pregnancy or by terminating a pathological pregnancy.

Doctors emphasize that for future parents, the ideal option is to analyze for genetic diseases at the stage of pregnancy planning.

Thus, the risk of transmitting hereditary disorders to the unborn baby is assessed. For this, a couple planning a pregnancy is advised to consult a geneticist. Only the DNA of future parents allows us to assess the risks of having children with genetic diseases. In this way, the health of the unborn child as a whole is also predicted.

The undoubted advantage of genetic analysis is that it can even prevent miscarriage. But, unfortunately, according to statistics, women resort to genetic analyzes most often after a miscarriage.

What influences the birth of unhealthy children

So, genetic analyzes allow us to assess the risks of having unhealthy children. That is, a geneticist can state that the risk of having a baby with Down syndrome, for example, is 50 to 50. What factors affect the health of the unborn child? Here they are:

1. The age of the parents. With age, genetic cells accumulate more and more “breakdowns”. This means that the older the father and mother, the higher the risk of having a baby with Down syndrome.
2. Close relationship of parents. Both cousins ​​and second cousins ​​are more likely to carry the same diseased genes.
3. The birth of sick children to parents or direct relatives increases the chances of having another baby with genetic diseases.
4. Chronic diseases of a family nature. If both father and mother suffer, for example, from multiple sclerosis, then the probability of the disease and the unborn baby is very high.
5. Parents belonging to certain ethnic groups. For example, Gaucher's disease, manifested by damage to the bone marrow and dementia, is more common among Ashkenazi Jews, Wilson's disease - among the peoples of the Mediterranean.
6. Unfavorable environment. If future parents live near a chemical plant, a nuclear power plant, a cosmodrome, then polluted water and air contribute to gene mutations in children.
7. Exposure to radiation on one of the parents is also an increased risk of gene mutations.

So, today, future parents have every chance and opportunity to avoid the birth of sick children. Responsible attitude to pregnancy, its planning will allow you to fully feel the joy of motherhood and fatherhood.

Especially for - Diana Rudenko

Genetic diseases are diseases that occur in humans due to chromosomal mutations and defects in genes, that is, in the hereditary cellular apparatus. Damage to the genetic apparatus leads to serious and varied problems - hearing loss, visual impairment, delayed psycho-physical development, infertility and many other diseases.

The concept of chromosomes

Each cell of the body has a cell nucleus, the main part of which is chromosomes. A set of 46 chromosomes is a karyotype. 22 pairs of chromosomes are autosomes, and the last 23 pairs are sex chromosomes. These are the sex chromosomes that men and women differ from each other.

Everyone knows that in women the composition of chromosomes is XX, and in men - XY. When a new life arises, the mother passes on the X chromosome, and the father either X or Y. It is with these chromosomes, or rather with their pathology, that genetic diseases are associated.

The gene can mutate. If it is recessive, then the mutation can be passed from generation to generation without showing up in any way. If the mutation is dominant, then it will definitely manifest itself, so it is advisable to protect your family by learning about the potential problem in time.

Genetic diseases are a problem of the modern world.

Hereditary pathology every year comes to light more and more. More than 6,000 names of genetic diseases are already known, they are associated with both quantitative and qualitative changes in the genetic material. According to the World Health Organization, approximately 6% of children suffer from hereditary diseases.

The most unpleasant thing is that genetic diseases can manifest themselves only after a few years. Parents rejoice in a healthy baby, not suspecting that the children are sick. So, for example, some hereditary diseases can manifest themselves at the age when the patient himself has children. And half of these children may be doomed if the parent carries the dominant pathological gene.

But sometimes it is enough to know that the child's body is not able to absorb a certain element. If parents are warned about this in time, then in the future, simply avoiding products containing this component, you can protect the body from manifestations of a genetic disease.

Therefore, it is very important that a test for genetic diseases be done when planning a pregnancy. If the test shows the likelihood of passing the mutated gene to the unborn child, then in German clinics they can carry out gene correction during artificial insemination. Testing can also be done during pregnancy.

In Germany, you can be offered innovative technologies of the latest diagnostic developments that can dispel all your doubts and suspicions. About 1,000 genetic diseases can be identified even before the birth of a child.

Genetic diseases - what are the types?

We will look at two groups of genetic diseases (in fact there are more)

1. Diseases with a genetic predisposition.

Such diseases can manifest themselves under the influence of external environmental factors and are very dependent on individual genetic predisposition. Some diseases may appear in the elderly, while others may appear unexpectedly and early. So, for example, a strong blow to the head can provoke epilepsy, the intake of an indigestible product can cause severe allergies, etc.

2. Diseases that develop in the presence of a dominant pathological gene.

These genetic diseases are passed down from generation to generation. For example, muscular dystrophy, hemophilia, six-fingeredness, phenylketonuria.

Families at high risk of having a child with a genetic disease.

Which families need to attend genetic counseling in the first place and identify the risk of hereditary diseases in their offspring?

1. Consanguineous marriages.

2. Infertility of unknown etiology.

3. Age of parents. It is considered a risk factor if the expectant mother is over 35 years old, and the father is over 40 (according to some sources, over 45). With age, more and more damage appears in the germ cells, which increase the risk of having a baby with a hereditary pathology.

4. Hereditary family diseases, that is, similar diseases in two or more family members. There are diseases with pronounced symptoms and there is no doubt that this is a hereditary disease in parents. But there are signs (microanomalies) that parents do not pay due attention to. For example, an unusual shape of the eyelids and ears, ptosis, coffee-colored spots on the skin, a strange smell of urine, sweat, etc.

5. Aggravated obstetric history - stillbirth, more than one spontaneous miscarriage, missed pregnancies.

6. Parents are representatives of a small ethnic group or people from one small locality (in this case, there is a high probability of consanguineous marriages)

7. The impact of adverse household or professional factors on one of the parents (calcium deficiency, insufficient protein nutrition, work in a printing house, etc.)

8. Bad ecological situation.

9. The use of drugs with teratogenic properties during pregnancy.

10. Diseases, especially viral etiology (rubella, chickenpox), which the pregnant woman has suffered.

11. Unhealthy lifestyle. Constant stress, alcohol, smoking, drugs, poor nutrition can cause damage to genes, since the structure of chromosomes under the influence of adverse conditions can change throughout life.

Genetic diseases - what are the methods for determining the diagnosis?

In Germany, the diagnosis of genetic diseases is highly effective, since all known high-tech methods and absolutely all the possibilities of modern medicine (DNA analysis, DNA sequencing, genetic passport, etc.) are used to identify potential hereditary problems. Let's dwell on the most common.

1. Clinical and genealogical method.

This method is an important condition for the qualitative diagnosis of a genetic disease. What does it include? First of all, a detailed survey of the patient. If there is a suspicion of a hereditary disease, then the survey concerns not only the parents themselves, but also all relatives, that is, complete and thorough information is collected about each family member. Subsequently, a pedigree is compiled indicating all signs and diseases. This method ends with a genetic analysis, on the basis of which the correct diagnosis is made and the optimal therapy is selected.

2. Cytogenetic method.

Thanks to this method, diseases that arise due to problems in the chromosomes of a cell are determined. The cytogenetic method examines the internal structure and arrangement of chromosomes. This is a very simple technique - a scraping is taken from the mucous membrane of the inner surface of the cheek, then the scraping is examined under a microscope. This method is carried out with parents, with family members. A variation of the cytogenetic method is molecular cytogenetic, which allows you to see the smallest changes in the structure of chromosomes.

3. Biochemical method.

This method, by examining the biological fluids of the mother (blood, saliva, sweat, urine, etc.), can determine hereditary diseases based on metabolic disorders. Albinism is one of the most well-known genetic diseases associated with metabolic disorders.

4. Molecular genetic method.

This is the most progressive method at present, which determines monogenic diseases. It is very accurate and detects pathology even in the nucleotide sequence. Thanks to this method, it is possible to determine the genetic predisposition to the development of oncology (cancer of the stomach, uterus, thyroid gland, prostate, leukemia, etc.). Therefore, it is especially indicated for people whose close relatives suffered from endocrine, mental, oncological and vascular diseases.

In Germany, for the diagnosis of genetic diseases, you will be offered the whole range of cytogenetic, biochemical, molecular genetic studies, prenatal and postnatal diagnostics, plus neonatal screening of the newborn. Here you can take about 1000 genetic tests that are approved for clinical use in the country.

Pregnancy and genetic diseases

Prenatal diagnosis provides great opportunities for determining genetic diseases.

Prenatal diagnosis includes tests such as

• chorion biopsy - analysis of the tissue of the chorionic membrane of the fetus at 7-9 weeks of pregnancy; a biopsy can be performed in two ways - through the cervix or by puncturing the anterior abdominal wall;
• amniocentesis - at 16-20 weeks of gestation, amniotic fluid is obtained due to puncture of the anterior abdominal wall;
• cordocentesis is one of the most important diagnostic methods, as it examines the fetal blood obtained from the umbilical cord.

Also in the diagnosis, screening methods such as triple test, fetal echocardiography, and alpha-fetoprotein determination are used.

Ultrasound imaging of the fetus in 3D and 4D measurements can significantly reduce the birth of babies with malformations. All these methods have a low risk of side effects and do not adversely affect the course of pregnancy. If a genetic disease is detected during pregnancy, the doctor will offer certain individual tactics for managing a pregnant woman. In the early period of pregnancy in German clinics, gene correction can be offered. If the correction of genes is carried out in the embryonic period on time, then some genetic defects can be corrected.

Neonatal screening of a child in Germany

Neonatal screening of the newborn reveals the most common genetic diseases in the infant. Early diagnosis allows you to understand that the child is sick even before the first signs of the disease appear. Thus, the following hereditary diseases can be identified - hypothyroidism, phenylketonuria, maple syrup disease, adrenogenital syndrome, and others.

If these diseases are detected in time, then the chance of curing them is quite high. High-quality neonatal screening is also one of the reasons why women fly to Germany to give birth here.

Treatment of human genetic diseases in Germany

More recently, genetic diseases were not treated, it was considered impossible, and therefore unpromising. Therefore, the diagnosis of a genetic disease was regarded as a sentence, and at best, one could only count on symptomatic treatment. Now the situation has changed. Progress is noticeable, positive results of treatment have appeared, moreover, science is constantly discovering new and effective ways to treat hereditary diseases. And although it is still impossible to cure many hereditary diseases today, geneticists are optimistic about the future.

Treatment of genetic diseases is a very complex process. It is based on the same principles of influence as any other disease - etiological, pathogenetic and symptomatic. Let's briefly look at each.

1. Etiological principle of influence.

The etiological principle of exposure is the most optimal, since the treatment is directed directly at the causes of the disease. This is achieved using methods of gene correction, isolation of the damaged part of DNA, its cloning and introduction into the body. At the moment, this task is very difficult, but in some diseases it is already feasible.

2. Pathogenetic principle of influence.

The treatment is aimed at the mechanism of the development of the disease, that is, it changes the physiological and biochemical processes in the body, eliminating the defects caused by the pathological gene. As genetics develops, the pathogenetic principle of influence expands, and for various diseases every year there will be new ways and possibilities for correcting broken links.

3. Symptomatic principle of influence.

According to this principle, the treatment of a genetic disease is aimed at relieving pain and other unpleasant phenomena and preventing the further progression of the disease. Symptomatic treatment is always prescribed, it can be combined with other methods of exposure, or it can be an independent and only treatment. This is the appointment of painkillers, sedatives, anticonvulsants and other drugs. The pharmaceutical industry is now very developed, so the range of drugs used to treat (or rather, to alleviate manifestations of) genetic diseases is very wide.

In addition to drug treatment, symptomatic treatment includes the use of physiotherapy procedures - massage, inhalation, electrotherapy, balneotherapy, etc.

Sometimes a surgical method of treatment is used to correct deformities, both external and internal.

German geneticists already have extensive experience in the treatment of genetic diseases. Depending on the manifestation of the disease, on individual parameters, the following approaches are used:

• genetic dietetics;
• gene therapy,
• stem cell transplant,
• transplantation of organs and tissues,
• enzyme therapy,
• replacement therapy with hormones and enzymes;
• hemosorption, plasmophoresis, lymphosorption - cleaning the body with special preparations;
• surgery.

Of course, the treatment of genetic diseases is long and not always successful. But every year the number of new approaches to therapy is growing, so doctors are optimistic.

Gene therapy

Doctors and scientists all over the world place special hopes on gene therapy, thanks to which it is possible to introduce high-quality genetic material into the cells of a diseased organism.

Gene correction consists of the following steps:

• obtaining genetic material (somatic cells) from the patient;
• introduction of a therapeutic gene into this material, which corrects the gene defect;
• cloning of corrected cells;
• the introduction of new healthy cells into the patient's body.

Gene correction requires great care, since science does not yet have complete information about the work of the genetic apparatus.

List of genetic diseases that can be identified

There are many classifications of genetic diseases, they are conditional and differ in the principle of construction. Below we provide a list of the most common genetic and hereditary diseases:

• Gunther's disease;
• Canavan disease;
• Niemann-Pick disease;
• Tay-Sachs disease;
• Charcot-Marie disease;
• hemophilia;
• hypertrichosis;
• color blindness - immunity to color, color blindness is transmitted only with the female chromosome, but only men suffer from the disease;
• Capgras delusion;
• leukodystrophy of Peliceus-Merzbacher;
• Blaschko lines;
• micropsia;
• cystic fibrosis;
• neurofibromatosis;
• heightened reflection;
• porphyria;
• progeria;
• spina bifida;
• Angelman syndrome;
• exploding head syndrome;
• blue skin syndrome;
• Down syndrome;
• living corpse syndrome;
• Joubert's syndrome;
• stone man syndrome
• Klinefelter's syndrome;
• Klein-Levin syndrome;
• Martin-Bell syndrome;
• Marfan syndrome;
• Prader-Willi syndrome;
• Robin's syndrome;
• Stendhal syndrome;
• Turner syndrome;
• elephant disease;
• phenylketonuria.
• cicero and others.

In this section, we will dwell on each disease in detail and tell you how you can cure some of them. But it is better to prevent genetic diseases than to treat them, especially since modern medicine does not know how to cure many diseases.

Genetic diseases are a group of diseases that are very heterogeneous in their clinical manifestations. The main external manifestations of genetic diseases:

• small head (microcephaly);
• microanomalies ("third eyelid", short neck, unusually shaped ears, etc.)
• delayed physical and mental development;
• change in the genitals;
• excessive muscle relaxation;
• change in the shape of the toes and hands;
• psychological disorder, etc.

Genetic diseases - how to get a consultation in Germany?

A conversation at a genetic consultation and prenatal diagnosis can prevent severe hereditary diseases that are transmitted at the gene level. The main goal of counseling with a geneticist is to identify the degree of risk of a genetic disease in a newborn.

In order to receive high-quality counseling and advice on further actions, one must seriously tune in to communication with the doctor. Before the consultation, it is necessary to responsibly prepare for the conversation, remember the illnesses that relatives suffered, describe all health problems and write down the main questions that you would like to receive answers to.

If the family already has a child with an anomaly, with congenital malformations, capture his photographs. Be sure to tell about spontaneous miscarriages, about cases of stillbirth, about how the pregnancy went (goes).

A genetic counseling doctor will be able to calculate the risk of a baby with a severe hereditary pathology (even in the future). When can we talk about a high risk of developing a genetic disease?

• genetic risk up to 5% is considered low;
• no more than 10% - the risk is slightly increased;
• from 10% to 20% - medium risk;
• above 20% - the risk is high.

Doctors advise considering a risk of about or above 20% as a reason for terminating a pregnancy or (if not already) as a contraindication to conception. But the final decision is made, of course, by the couple.

The consultation can take place in several stages. When diagnosing a genetic disease in a woman, the doctor develops tactics for managing it before pregnancy and, if necessary, during pregnancy. The doctor tells in detail about the course of the disease, life expectancy in this pathology, about all the possibilities of modern therapy, about the price component, about the prognosis of the disease. Sometimes gene correction during artificial insemination or during embryonic development avoids the manifestations of the disease. Every year, new methods of gene therapy and the prevention of hereditary diseases are being developed, so the chances of curing a genetic pathology are constantly increasing.

In Germany, methods of combating gene mutations with the help of stem cells are being actively introduced and are already being successfully applied, new technologies are being considered for the treatment and diagnosis of genetic diseases.

From parents, a child can acquire not only a certain eye color, height or face shape, but also inherited. What are they? How can you discover them? What classification exists?

Mechanisms of heredity

Before talking about diseases, it is worth understanding what all the information about us is contained in the DNA molecule, which consists of an unimaginably long chain of amino acids. The alternation of these amino acids is unique.

Fragments of the DNA chain are called genes. Each gene contains integral information about one or more characteristics of the body, which is transmitted from parents to children, for example, skin color, hair, character trait, etc. When they are damaged or their work is disturbed, genetic diseases are inherited.

DNA is organized into 46 chromosomes or 23 pairs, one of which is sexual. Chromosomes are responsible for the activity of genes, their copying, as well as repair in case of damage. As a result of fertilization, each pair has one chromosome from the father and the other from the mother.

In this case, one of the genes will be dominant, and the other recessive or suppressed. Simply put, if the gene responsible for eye color is dominant in the father, then the child will inherit this trait from him, and not from the mother.

Genetic diseases

Hereditary diseases occur when abnormalities or mutations occur in the mechanism for storing and transmitting genetic information. An organism whose gene is damaged will pass it on to its offspring in the same way as healthy material.

In the case when the pathological gene is recessive, it may not appear in the next generations, but they will be its carriers. The chance that it will not manifest itself exists when a healthy gene also turns out to be dominant.

Currently, more than 6 thousand hereditary diseases are known. Many of them appear after 35 years, and some may never declare themselves to the owner. Diabetes mellitus, obesity, psoriasis, Alzheimer's disease, schizophrenia and other disorders are manifested with extremely high frequency.

Classification

Genetic diseases that are inherited have a huge number of varieties. To separate them into separate groups, the location of the disorder, causes, clinical picture, and the nature of heredity can be taken into account.

Diseases can be classified according to the type of inheritance and the location of the defective gene. So, it is important whether the gene is located on the sex or non-sex chromosome (autosome), and whether it is suppressive or not. Allocate diseases:

• Autosomal dominant - brachydactyly, arachnodactyly, ectopia of the lens.
• Autosomal recessive - albinism, muscular dystonia, dystrophy.
• Sex-limited (observed only in women or men) - hemophilia A and B, color blindness, paralysis, phosphate diabetes.

The quantitative and qualitative classification of hereditary diseases distinguishes gene, chromosomal and mitochondrial types. The latter refers to DNA disturbances in mitochondria outside the nucleus. The first two occur in DNA, which is located in the cell nucleus, and have several subtypes:

Causes

Our genes tend not only to accumulate information, but also to change it, acquiring new qualities. This is the mutation. It occurs quite rarely, about 1 time in a million cases, and is transmitted to descendants if it occurs in germ cells. For individual genes, the mutation rate is 1:108.

Mutations are a natural process and form the basis of the evolutionary variability of all living beings. They can be helpful and harmful. Some help us to better adapt to the environment and way of life (for example, the opposed thumb), others lead to diseases.

The occurrence of pathologies in the genes is increased by physical, chemical and biological. This property is possessed by some alkaloids, nitrates, nitrites, some food additives, pesticides, solvents and petroleum products.

Among the physical factors are ionizing and radioactive radiation, ultraviolet rays, excessively high and low temperatures. The biological causes are rubella viruses, measles, antigens, etc.

genetic predisposition

Parents influence us not only by education. It is known that some people are more likely to develop certain diseases than others due to heredity. A genetic predisposition to diseases occurs when one of the relatives has an abnormality in the genes.

The risk of a particular disease in a child depends on his gender, because some diseases are transmitted only through one line. It also depends on the race of the person and on the degree of relationship with the patient.

If a child is born to a person with a mutation, then the chance of inheriting the disease will be 50%. The gene may well not show itself in any way, being recessive, and in the case of marriage with a healthy person, its chances of being passed on to descendants will be already 25%. However, if the spouse also owns such a recessive gene, the chances of its manifestation in descendants will again increase to 50%.

How to identify the disease?

The genetic center will help to detect the disease or predisposition to it in time. Usually this is in all major cities. Before taking the tests, a consultation is held with the doctor to find out what health problems are observed in relatives.

Medico-genetic examination is carried out by taking blood for analysis. The sample is carefully examined in the laboratory for any abnormalities. Expectant parents usually attend such consultations after pregnancy. However, it is worth coming to the genetic center during its planning.

Hereditary diseases seriously affect the mental and physical health of the child, affect life expectancy. Most of them are difficult to treat, and their manifestation is only corrected by medical means. Therefore, it is better to prepare for this even before conceiving a baby.

Down syndrome

One of the most common genetic diseases is Down syndrome. It occurs in 13 cases out of 10,000. This is an anomaly in which a person has not 46, but 47 chromosomes. The syndrome can be diagnosed immediately at birth.

Among the main symptoms are a flattened face, raised corners of the eyes, a short neck, and a lack of muscle tone. The auricles are usually small, the incision of the eyes is oblique, the irregular shape of the skull.

In sick children, concomitant disorders and diseases are observed - pneumonia, SARS, etc. Exacerbations are possible, for example, hearing loss, vision loss, hypothyroidism, heart disease. With Downism, it is slowed down and often remains at the level of seven years.

Constant work, special exercises and preparations significantly improve the situation. Many cases are known when people with a similar syndrome could well lead an independent life, find work and achieve professional success.

Hemophilia

A rare hereditary disease that affects men. Occurs once in 10,000 cases. Hemophilia is not treated and occurs as a result of a change in one gene on the sex X chromosome. Women are only carriers of the disease.

The main characteristic is the absence of a protein that is responsible for blood clotting. In this case, even a minor injury causes bleeding that is not easy to stop. Sometimes it manifests itself only the next day after the bruise.

Queen Victoria of England was a carrier of hemophilia. She passed on the disease to many of her descendants, including Tsarevich Alexei, the son of Tsar Nicholas II. Thanks to her, the disease began to be called "royal" or "Victorian".

Angelman syndrome

The disease is often called "happy doll syndrome" or "Petrushka syndrome", as patients have frequent outbursts of laughter and smiles, chaotic hand movements. With this anomaly, a violation of sleep and mental development is characteristic.

The syndrome occurs once in 10,000 cases due to the absence of certain genes in the long arm of the 15th chromosome. Angelman's disease develops only if the genes are missing from the chromosome inherited from the mother. When the same genes are missing from the paternal chromosome, Prader-Willi syndrome occurs.

The disease cannot be cured completely, but it is possible to alleviate the manifestation of symptoms. For this, physical procedures and massages are carried out. Patients do not become completely independent, but during treatment they can serve themselves.

All couples, dreaming of a child, want the baby to be born without fail healthy. But there is a possibility that, despite all the efforts made, the child will be born seriously ill. Often this happens due to genetic diseases that happened in the family of one of the parents or even two. What are the most common genetic diseases?

The likelihood of a genetic disease in a child

It is believed that the probability of having a baby with a congenital or hereditary pathology, the so-called population or general statistical risk, is approximately 3-5% for each pregnant woman. In rare cases, the probability of the birth of a child with a genetic disease can be predicted and the pathology can be diagnosed already in the period of intrauterine development of the child. Certain congenital malformations and diseases are established using laboratory biochemical, cytogenetic and molecular genetic methods even in the fetus, since some diseases are detected during a complex of prenatal (prenatal) diagnostic methods.

Down syndrome

The most common disease caused by a change in the set of chromosomes is Down's disease, which occurs in one child in 700 newborns. This diagnosis in a child should be made by a neonatologist in the first 5-7 days after birth and confirmed by examining the child's karyotype. In the presence of Down's disease in a child, the karyotype is 47 chromosomes, when with 21 pairs there is a third chromosome. Girls and boys are susceptible to Down's disease with the same frequency.

Shereshevsky-Turner disease occurs only in girls. Signs of this pathology can become noticeable at the age of 10-12, when the girl's height is too small, and the hair on the back of her head is set too low. At 13-14 years old, a girl suffering from this disease does not even have any hints of menstruation. There is also mild mental retardation. The main symptom in adult girls with Shereshevsky-Turner disease is infertility. The karyotype of such a patient is 45 chromosomes, one X chromosome is missing.

Klinefelter's disease

Kleinfelter's disease occurs only in men, the diagnosis of this disease is most often established at the age of 16-18. A sick young man has a very high growth - from 190 cm and above, while mental retardation is often observed, and disproportionately long arms are noted, which can completely cover the chest. In the study of the karyotype, 47 chromosomes are found - 47, XXY. In adult men with Klinefelter's disease, infertility is the main symptom.

With phenylketonuria, or pyruvic oligophrenia, which is a hereditary disease, the parents of a sick child can be quite healthy people, but each of them can be a carrier of exactly the same pathological gene, while the risk that they can have a sick child is about 25%. Most often, such cases occur in related marriages. Phenylketonuria is one of the most common hereditary diseases, with an incidence of 1:10,000 newborns. The essence of phenylketonuria is that the amino acid phenylalanine is not absorbed by the body, while the toxic concentration adversely affects the functional activity of the brain and a number of other organs and systems of the child. There is a lag in the mental and motor development of the baby, epileptiform-like seizures, dyspeptic manifestations and dermatitis are the main clinical signs of this disease. Treatment consists of a special diet, as well as the additional use of amino acid mixtures devoid of the amino acid phenylalanine.

Hemophilia

Hemophilia most often manifests itself only after a year of a child's life. Mostly boys suffer from this disease, but mothers are most often carriers of this genetic mutation. The bleeding disorder that occurs in hemophilia often leads to severe joint damage, such as hemorrhagic arthritis and other body lesions, when the slightest cuts cause prolonged bleeding, which can be fatal to a person.