Treatment of genetic diseases in children. Hereditary diseases

Bacteria, viruses and infections are not always the cause of the disease. Some diseases are programmed in us even before birth. 70% of people have some deviations from the norm in their genotype. In other words, faulty genes. But out of 70%, not all have genetic diseases. What are the most common genetic diseases?

What is a genetic disease

A genetic disease is a disease caused by damage to the software apparatus of cells. Since they are inherited, they are also called hereditary diseases. These diseases are transmitted only from parents to children, there are no other ways of infection.

Down Syndrome With Down syndrome, 1 child is born in 1100. People with this chromosomal abnormality are significantly behind in physical and mental development. Spina bifida With such a violation, 1 child is born out of 500-2000 children. Although in early age you can correct the anomaly with surgery, the risk of complications is too great. Cystic fibrosis The disease is the cause of disturbances in the functioning of the excretory glands, digestive and respiratory systems. In European countries, the frequency of this genetic mutation is 1: 2000 - 1: 2500. Neurofibromatosis This common genetic disorder is characterized by the appearance of many small tumors in the patient. It occurs in one out of 3500 newborns. Color blindness Violations in the gene code lead to color recognition problems. There are many types of color blindness, depending on what color the patient does not perceive with his eyes. 2-8% of men suffer from various degrees of color blindness, and only 0.4% of women. Klinefelter's syndrome One in 500 newborn boys has this anomaly. It manifests itself in high growth, large body weight and a large number of female hormones. All patients suffer from infertility. Prader-Willi syndrome Occurs once every 12-15 thousand newborns, patients are short and obese. You can help patients with medication. Turner syndrome This gene disorder occurs in 1 in 2,500 newborn girls. All patients have short stature, increased body weight and short fingers. Angelman syndrome Symptoms of the disease: developmental delay, chaotic movements and emotional reactions, 80% of patients have epilepsy. With this disease, 1 child is born in 10 thousand. Hemophilia This incurable disease affects men. Hemophilia is a blood clotting disorder. Patients suffer from internal hemorrhages. The incidence of the disease is 1: 10000. Phenylketonuria This disease causes a violation of amino acid metabolism, and damage to the central nervous system... The incidence of the disease in European countries is 1: 10000.

Hereditary diseases are one of the worst diseases. There is simply no cure for many of them. Very often, parents are only carriers of the defective gene, and the disease is recouped in the child. Many male genetic diseases are maternal and vice versa. If Down's syndrome or spina bifida is diagnosed in a child while still in the womb, then she is offered an abortion. The life of most people with hereditary diseases is very difficult. But diseases such as color blindness, hemophilia, Turner syndrome and many others do not pose a great danger. You can live normally with them or cope with problems with hormonal drugs.

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 find them? What classification is there?

Heredity mechanisms

Before talking about diseases, it is worth understanding what it is All 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.

The fragments of the DNA chain are called genes. Each gene contains integral information about one or several traits of the organism, which is transmitted from parents to children, for example, the color of the skin, hair, character trait, etc. When they are damaged or disrupted, genetic diseases occur that are inherited.

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

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

Genetic diseases

Inherited diseases occur when disorders or mutations occur in the mechanism of storage and transmission of 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 future generations, but they will be its carriers. The chance that it will not show up exists when the healthy gene is also 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. With an extremely high frequency, diabetes, obesity, psoriasis, Alzheimer's disease, schizophrenia and other disorders.

Classification

Genetic diseases, inherited, have a huge number of varieties. To divide them into separate groups, the location of the violation, the reasons, clinical picture, the nature of heredity.

Diseases can be classified according to the type of inheritance and 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. Diseases are distinguished:

• 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 species. The latter refers to DNA abnormalities in mitochondria outside the nucleus. The first two occur in DNA, which is located in the cell nucleus, and have several subspecies:

Monogenic	Mutations or absence of a gene in nuclear DNA.	Marfan syndrome, adrenogenital syndrome in newborns, neurofibromatosis, hemophilia A, Duchenne myopathy.
Polygenic	Predisposition and action	Psoriasis, schizophrenia, ischemic disease, cirrhosis, bronchial asthma, diabetes.
Chromosomal
	Changes in the structure of chromosomes.	Syndromes Miller-Dicker, Williams, Langer-Gidion.
	Change in the number of chromosomes.	Down syndrome, Patau, Edwards, Clifenter.

Causes of occurrence

Our genes tend not only to accumulate information, but also to change it, acquiring new qualities. This is mutation. It happens quite rarely, about 1 time in a million cases, and is transmitted to descendants if it occurs in the 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 things. They can be useful and harmful. Some help us better adapt to the environment and way of life (for example, opposed thumb hands), others lead to disease.

The appearance of pathologies in genes is accelerated by physical, chemical and biological properties. Some alkaloids, nitrates, nitrites, some nutritional supplements, pesticides, solvents and petroleum products.

Among physical factors there are ionizing and radioactive radiation, ultraviolet rays, excessively high and low temperatures. The biological causes are rubella, 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. Genetic predisposition to disease occurs when a relative has a genetic disorder.

The risk of a particular disease in a child depends on his gender, because some diseases are transmitted only along 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 manifest 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 already be 25%. However, if the spouse also owns such a recessive gene, the chances of its manifestation in offspring 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. This is usually found in all major cities. Before taking the tests, a consultation with a doctor is carried out to find out what health problems are observed in relatives.

Medical genetic examination is carried out by taking blood for analysis. The sample is carefully examined in the laboratory for any abnormalities. Parents-to-be 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 and affect life expectancy. Most of them are difficult to treat, and their manifestation is only being corrected. 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 lack of muscle tone. Auricles, as a rule, small, slanting eyes, irregular shape of the skull.

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

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

Hemophilia

A rare hereditary disease affecting men. Occurs once every 10,000 cases. Hemophilia is untreated and results from 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 minor trauma causes bleeding that cannot be easily stopped. Sometimes it manifests itself only the next day after the injury.

Queen Victoria of England was a carrier of hemophilia. She transmitted 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 "Parsley's syndrome", as patients have frequent outbursts of laughter and smiles, chaotic hand movements. With this anomaly, sleep and mental development disorders are characteristic.

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

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

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All genetic diseases, of which several thousand are known today, are caused by abnormalities in human genetic material (DNA).

Genetic diseases can be associated with a mutation of one or more genes, with a violation of the location, absence or duplication of whole chromosomes (chromosomal diseases), as well as with maternally transmitted mutations in the genetic material of mitochondria (mitochondrial diseases).

More than 4000 single gene disorders alone have been described.

A little about genetic diseases

Medicine has long known that different ethnic groups have a predisposition to certain genetic diseases. For example, people from the Mediterranean Sea region are more likely to suffer from thalassemias. We know that the age of the mother strongly affects the risk of a number of genetic diseases in the child.

It is also known that some genetic diseases arose in us as an attempt by the body to resist the environment. Sickle cell anemia, according to modern data, originated in Africa, where for many thousands of years malaria was the real scourge of humanity. In sickle cell disease, humans have a red blood cell mutation that makes the host resistant to Plasmodium malaria.

Scientists today have developed tests for hundreds of genetic diseases. We can test for cystic fibrosis, Down syndrome, fragile X syndrome, hereditary thrombophilia, Bloom's syndrome, Canavan disease, Fanconi anemia, familial dysautonomy, Gaucher disease, Niemann-Pick disease, Klinefelter syndrome, thalassemias and many other diseases.

Cystic fibrosis.

Cystic fibrosis, known in English literature as cystic fibrosis, is one of the most common genetic diseases, especially in Caucasian and Ashkenazi Jews. It is caused by a deficiency of protein, which controls the balance of chloride in cells. The result of a deficiency of this protein is the thickening and violation of the properties of the secretion of the glands. Cystic fibrosis is manifested by dysfunctions of the respiratory system, digestive tract, the reproductive system. Symptoms can range from mild to very severe. For the disease to occur, both parents must be carriers of the defective genes.

Down Syndrome.

This is the most famous chromosomal disorder that occurs due to the presence of excess genetic material on chromosome 21. Down syndrome is recorded in 1 child per 800-1000 newborns. This disease is easy to detect with prenatal screening. The syndrome is characterized by anomalies in the structure of the face, decreased muscle tone, malformations of the cardiovascular and digestive systemas well as developmental lag. Children with Down syndrome have different symptoms, ranging from mild to very severe developmental disabilities. This disease is equally dangerous for all ethnic groups. The most important risk factor is the mother's age.

Fragile X syndrome.

Fragile X syndrome, or Martin-Bell syndrome, is associated with the most common type of congenital mental retardation. Developmental delays can be very mild or severe, and sometimes the syndrome is associated with autism. This syndrome is found in 1 in 1500 men and 1 in 2500 women. The disease is associated with the presence of abnormal repeating areas on the X chromosome - the more such areas, the more severe the disease progresses.

Hereditary coagulation disorders.

Blood clotting is one of the most complex biochemical processes occurring in the body, so there is a huge variety of clotting disorders at different stages. Clotting disorders can lead to a tendency to bleeding or, conversely, the formation of blood clots.

Among known diseases - thrombophilia associated with Leiden mutation (factor V Leiden). There are other genetic coagulation disorders, including prothrombin (factor II) deficiency, protein C deficiency, protein S deficiency, antithrombin III deficiency, etc.

Everyone has heard of hemophilia - a hereditary coagulation disorder in which dangerous hemorrhages occur during internal organs, muscles, joints, abnormal menstrual bleeding is observed, and any minor injury can lead to irreparable consequences due to the inability of the body to stop the bleeding. The most common is hemophilia A (coagulation factor VIII deficiency); also known hemophilia B (deficiency of factor IX) and hemophilia C (deficiency of factor XI).

There is also a very common von Willebrand disease, in which spontaneous bleeding occurs due to a low level of factor VIII. The disease was described in 1926 by the Finnish pediatrician von Willebrand. American researchers believe that 1% of the world's population suffers from it, but in most of them the genetic defect does not cause serious symptoms (for example, women can only have heavy periods). Clinically significant cases, in their opinion, are observed in 1 person in 10,000, that is, in 0.01%.

Familial hypercholesterolemia.

This is a group of hereditary metabolic disorders that manifest abnormally high level lipids and cholesterol in the blood. Familial hypercholesterolemia is associated with obesity, impaired glucose tolerance, diabetes, strokes and heart attacks. Treatments for the disease include lifestyle changes and a strict diet.

Huntington's disease.

Huntington's disease (sometimes Huntington's) is an inherited disorder that causes gradual degeneration of the central nervous system. Loss of function of nerve cells in the brain is accompanied by behavioral changes, unusual jerky movements (chorea), uncontrolled muscle contractions, difficulty walking, memory loss, speech and swallowing problems.

Modern treatment is aimed at combating the symptoms of the disease. Huntington's disease usually begins to manifest itself at the age of 30-40, and before that, a person may not be aware of his fate. Less often, the disease begins to progress already in childhood. This is an autosomal dominant disease - if one of the parents has a defective gene, then the child has a 50% chance of getting it.

Duchenne muscular dystrophy.

With Duchenne muscular dystrophy, symptoms usually appear before the age of 6 years. These include fatigue, muscle weakness (starting in the legs and going up), possible delay mental development, heart and respiratory problems, spinal deformity and chest... Progressive muscle weakness leads to disability; by the age of 12, many children are already confined to a wheelchair. Boys are sick.

Becker's muscular dystrophy.

With Becker muscular dystrophy, symptoms resemble Duchenne dystrophy, but occur later and develop more slowly. Muscle weakness in the upper body is not as severe as in the previous type of dystrophy. Boys are sick. The onset of the disease occurs at 10-15 years, and by the age of 25-30, patients are usually confined to a wheelchair.

Sickle cell anemia.

With this hereditary disease, the shape of red blood cells is disrupted, which become like a sickle - hence the name. The altered red blood cells cannot deliver enough oxygen to organs and tissues. The disease leads to severe crises that occur repeatedly or only a few times in the patient's life. In addition to pain in the chest, abdomen and bones, there is fatigue, shortness of breath, tachycardia, fever, etc.

Treatment includes pain relievers folic acid to support hematopoiesis, blood transfusions, dialysis, and hydroxyurea to reduce the frequency of episodes. Sickle cell anemia occurs predominantly in people of African and Mediterranean roots, as well as in South and Central America.

Thalassemias.

Thalassemias (beta-thalassemias and alpha-thalassemias) are a group of hereditary diseases in which the correct synthesis of hemoglobin is disrupted. As a result, anemia develops. Patients complain of fatigue, shortness of breath, bone pain, they have an increase in the spleen and fragility of the bones, poor appetite, dark urine, yellowness of the skin. Such people are susceptible to infectious diseases.

Phenylketonuria.

Phenylketonuria is the result of a deficiency in a liver enzyme that is required to convert the amino acid phenylalanine to another amino acid, tyrosine. If the disease is not diagnosed in time, large amounts of phenylalanine accumulate in the child's body, causing mental retardation, nervous system damage and seizures. Treatment consists of a strict diet and the use of the cofactor tetrahydrobiopterin (BH4) to lower blood phenylalanine levels.

Alpha-1-antitrypsin deficiency.

This disease occurs due to an insufficient amount of the enzyme alpha-1-antitropsin in the lungs and blood, which leads to consequences such as emphysema. Early symptoms of the disease include shortness of breath, wheezing. Other symptoms: weight loss, frequent respiratory infections, fatigue, tachycardia.

In addition to those listed above, there are many other genetic diseases. Today, there are no radical cures for them, but gene therapy has great potential. Many illnesses, especially when diagnosed early, can be successfully controlled and patients can live full, productive lives.

Content

A person during his life suffers many mild or serious illnesses, but in some cases he is born with them. Hereditary diseases or genetic disorders appear in a child due to a mutation of one of the DNA chromosomes, which leads to the development of an illness. Some of them carry only external changes, but there are a number of pathologies that threaten the baby's life.

What are hereditary diseases

These are genetic diseases or chromosomal abnormalities, the development of which is associated with a disturbance in the hereditary apparatus of cells transmitted through reproductive cells (gametes). The emergence of such hereditary pathologies is associated with the process of transmission, implementation, storage of genetic information. More and more men have a problem with this kind of deviation, so the chance of conceiving healthy child is getting smaller. Medicine is constantly researching to develop a procedure to prevent the birth of children with disabilities.

Causes

Genetic diseases of a hereditary type are formed by mutation of gene information. They can be detected immediately after the birth of the child or, after long time with a long development of pathology. There are three main reasons for the development of hereditary ailments:

• chromosomal abnormalities;
• chromosome abnormalities;
• gene mutations.

The latter reason is included in the group of hereditarily predisposed type, because environmental factors also affect their development and activation. A striking example of such diseases is considered hypertonic disease or diabetes mellitus. In addition to mutations, their progression is influenced by prolonged overstrain of the nervous system, unhealthy diet, mental trauma and obesity.

Symptoms

Each hereditary disease has its own specific characteristics. At the moment, more than 1600 different pathologies are known that cause genetic and chromosomal abnormalities. Manifestations differ in severity and brightness. To prevent the onset of symptoms, it is necessary to identify the probability of their occurrence in time. To do this, use the following methods:

1. Twin. Hereditary pathologies are diagnosed by studying the differences, the similarities of twins to determine the influence of genetic characteristics, the external environment on the development of diseases.
2. Genealogical. The likelihood of developing pathological or normal signs is studied using the person's pedigree.
3. Cytogenetic. The chromosomes of healthy and sick people are being investigated.
4. Biochemical. The human metabolism is monitored, the features of this process are highlighted.

In addition to these methods, most girls undergo ultrasound procedure... It helps determine the likelihood of occurrence of congenital defects development (from the 1st trimester), suggest the presence of a certain number of chromosomal diseases or hereditary ailments of the nervous system in the unborn child.

In children

The vast majority of diseases of a hereditary nature are manifested in childhood. Each of the pathologies has its own characteristics that are unique to each disease. There are a large number of anomalies, so they will be described in more detail below. Thanks to modern methods diagnostics to identify deviations in the development of the child, to determine the likelihood of hereditary diseases can be even during the gestation of the child.

Classification of hereditary human diseases

The grouping of diseases of a genetic nature is carried out because of their occurrence. The main types of hereditary diseases are:

1. Genetic - arise from DNA damage at the gene level.
2. Hereditary predisposition, autosomal recessive diseases.
3. Chromosomal abnormalities. Diseases occur as a result of the appearance of excess or loss of one of the chromosomes or their aberrations, deletions.

List of hereditary human diseases

Science knows more than 1,500 diseases that belong to the above categories. Some of them are extremely rare, but certain types are heard by many. The most famous are the following pathologies:

• albright's disease;
• ichthyosis;
• thalassemia;
• marfan syndrome;
• otosclerosis;
• paroxysmal myoplegia;
• hemophilia;
• fabry disease;
• muscular dystrophy;
• klinefelter's syndrome;
• down syndrome;
• shereshevsky-Turner syndrome;
• screaming syndrome;
• schizophrenia;
• congenital dislocation of the hip;
• heart defects;
• cleft palate and lip;
• syndactyly (fusion of fingers).

Which are the most dangerous

Of the above pathologies, there are those diseases that are considered dangerous to human life. As a rule, this list includes those abnormalities that have polysomy or trisomy in the chromosome set, when, instead of two, from 3 to 5 or more are observed. In some cases, 1 chromosome is found instead of 2. All such anomalies are the result of abnormalities in cell division. With such a pathology, the child lives up to 2 years, if the deviations are not very serious, then he lives up to 14 years. The most dangerous ailments are:

• canavan disease;
• edwards syndrome;
• hemophilia;
• patau syndrome;
• spinal muscular amyotrophy.

Down Syndrome

The disease is inherited when both or one of the parents has defective chromosomes. Down syndrome develops due to trisomy21 chromosome (instead of 2, there are 3). children with this ailment suffer from strabismus, have an abnormal shape of the ears, a crease in the neck, mental retardation and heart problems. This chromosome anomaly is not life-threatening. According to statistics, 1 out of 800 is born with this syndrome. Women who want to give birth after 35 are more likely to have a baby with Down (1 in 375), after 45 years the probability is 1 in 30.

Acrocraniodysphalangia

The disease has an autosomal dominant type of inheritance of the anomaly, the cause is a violation in chromosome 10. Scientists call the disease acrocraniodysphalangia or Apert's syndrome. It is characterized by the following symptoms:

• violation of the ratio of the length and width of the skull (brachycephaly);
• high blood pressure (hypertension) forms inside the skull due to the fusion of coronary sutures;
• syndactyly;
• mental retardation against the background of compression of the brain by the skull;
• bulging forehead.

What are the possibilities of treating hereditary diseases

Doctors are constantly working on the problem of gene and chromosome abnormalities, but all treatment at this stage is reduced to suppressing symptoms, and it is not possible to achieve complete recovery. Therapy is selected depending on the pathology in order to reduce the severity of symptoms. The following treatment options are often used:

1. An increase in the amount of incoming coenzymes, for example, vitamins.
2. Diet therapy. An important point that helps to get rid of a number of unpleasant consequences of hereditary anomalies. If the diet is violated, a sharp deterioration in the patient's condition is immediately observed. For example, with phenylketonuria, foods that contain phenylalanine are completely excluded from the diet. Failure to take this measure can lead to severe idiocy, so doctors focus on the need for diet therapy.
3. Consumption of those substances that are absent in the body due to the development of pathology. For example, with orotaciduria, he prescribes cytidylic acid.
4. In case of metabolic disorders, it is necessary to ensure timely cleansing of the body from toxins. Wilson-Konovalov's disease (copper accumulation) is stopped by taking d-penicillamine, and hemoglobinopathy (iron accumulation) - by desferal.
5. Inhibitors help block excessive enzyme activity.
6. Transplantation of organs, tissue sites, cells that contain normal genetic information is possible.

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 people are 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 regularity of the development of defects are unclear, 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 genetic structure. Deviations can occur in one gene or in several.

Hereditary diseases:

1. Autosomal dominant.
2. Autosomal recessive.
3. Floor-locked.
4. Chromosomal diseases.

The probability of an autosomal dominant disorder is 50%. With autosomal recessive - 25%. Sex-linked diseases are those that a damaged X chromosome carries with it.

Hereditary diseases

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

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

Recessive:

• Phenylketonuria.
• Ichthyosis.
• Others.

Sex-linked diseases:

• Hemophilia.
• Muscular dystrophy.
• Farby's disease.

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

• Shareshevsky-Turner syndrome.
• Down Syndrome.

Polygenic diseases include:

• Dislocated hip (congenital).
• Heart defects.
• Schizophrenia.
• Cleft lip and palate.

The most common gene abnormality is syndactyly. That is, fusion of fingers. Syndactyly is the most harmless 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 instead of a pair of chromosomes, the presence of 3, 4, 5 or more is observed. There is also 1 chromosome instead of 2. All these deviations are due to a violation of cell division.

The most dangerous hereditary human 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 may live to be 7, 8, or even 14 years old.

Down Syndrome

Down syndrome is inherited when one or both parents carry defective chromosomes. More specifically, the syndrome is associated with chromosomes (i.e. 21 chromosomes 3, not 2). Children with Down syndrome have squint, neck crease, abnormal ears, heart problems, and mental retardation. But for the life of newborns, the chromosomal abnormality does not carry any 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 features of the body structure as:

• brachycephaly (violation of the ratio of the width and length of the skull);
• fusion of the coronary sutures of the skull, as a result of which there is hypertension (increased blood pressure inside the skull);
• syndactyly;
• bulging 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 prescribed surgery to enlarge the skull to restore 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 2 children will be born with the same deviation is very high.

Happy Doll Syndrome and Canavan-Van Bogart-Bertrand Disease

Let us consider these diseases in more detail. Engelmann's syndrome can be recognized somewhere from 3-7 years old. Children have seizures poor digestion, problems with coordination of movements. Most of them have squint and problems with the muscles of the face, which is why they often smile on their faces. The child's movements are very constrained. This is understandable for doctors 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 inarticulate.

The reason a child has the syndrome is a problem on chromosome 15. The disease is extremely rare - 1 case per 15 thousand births.

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

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

1. Macrocephaly.
2. Convulsions 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, hereditary human diseases are very diverse. The list, given as an example only, is far from complete.

I would like to note that if both parents have a disorder in 1 and the same gene, then the chances of having a sick child are great, but if there are abnormalities in different genes, then there is no need to fear. It is known that in 60% of cases, chromosomal abnormalities in the embryo lead to miscarriage. Yet 40% of these children are born and fight for their lives.