Hereditary diseases of man. List. The most common and dangerous diseases

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 hereditary human diseases are studied, the list of which is huge.

The male population has more and more genetic defects and is less likely to conceive a healthy child. While all the causes of the development of vices are unclear, one can assume that in the nearest 100-200 years science will cope with the solution of these problems.

What are genetic diseases? Classification

Genetics as a science began its own research path since 1900. Genetic diseases are those that are associated with deviations in the gene structure of a person. Deviations can occur in either a gene or in several.

Hereditary diseases:

1. Autosomal dominant.
2. Autosomal recessive.
3. Clutched with the floor.
4. Chromosomal diseases.

The probability of a child's illness in autosomal dominant deviation is 50%. At autosomal recessive - 25%. Diseases linked to the sex are those that carry a damaged X chromosome.

Hereditary diseases

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

• Marfan's syndrome.
• Paroxysmal myoplegia.
• Thalassemia.
• Albright's disease.
• . Otosclerosis .

Recessive:

• Phenylketonuria.
• Ichthyosis.
• Others.

Sex-linked diseases:

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

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

• Syndrome Shareshevsky-Turner.
• Klinefelter's syndrome.
• Cats scream syndrome.
• Down Syndrome.

The polygenic diseases include:

• Hip dislocation (congenital).
• Heart defects.
• Schizophrenia.
• Splitting of the lips and the sky.

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

What diseases are most dangerous

Of those listed diseases can be identified the most dangerous hereditary human diseases. The list of them consists of those types of anomalies, where trisomy or polysomy occurs in the chromosome set, that is, when 3, 4, 5 or more are present 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 hereditary human diseases:

• Edwards Syndrome.
• Spinal muscular amyotrophy.
• Syndrome Patau.
• Canavan's disease.
• Hemophilia.
• Other diseases.

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

Down Syndrome

Down syndrome is inherited if one or both parents are carriers of defective chromosomes. More precisely, the syndrome is associated with trisomy of 21 chromosomes (ie, 21 chromosomes 3, not 2). Children with Down's syndrome have strabismus, a crease on the neck, an abnormal shape of the ears, heart problems and mental retardation. But for the life of newborns, chromosomal abnormality does not carry.

Now the statistics claims that of 700-800 children 1 is born with this syndrome. Women who want to have a child after 35 are more likely to give birth to such a baby. Probability is somewhere 1 to 375. But a woman who decided to have a baby in 45, has a probability of 1 to 30.

Acrocraniodisphalange

Type of inheritance anomaly - autosomal dominant. The cause of the syndrome is a disorder in the 10 chromosome. In science, this disease is called acrokraniodisphalange, if it is easier, then Apert syndrome. Characterized by such features of the structure of the body, as:

• Brachycephaly (violation of the ratio of width and length of the skull);
• Fusion of the coronary sutures of the skull, as a result of which hypertension is observed (high blood pressure inside the skull);
• Syndactyly;
• Convex forehead;
• Often mental retardation on the background of the fact that the skull squeezes the brain and does not allow the growth of nerve cells.

In our time, children with Apert syndrome are prescribed a surgery to increase the skull to restore blood pressure. And mental underdevelopment is treated with stimulants.

If the family has a child who has a syndrome diagnosed, the likelihood that the 2 children will be born with the same deviation is very high.

Syndrome of a happy doll and Canavan-van-Bogart-Bertrand disease

Let us also consider these diseases in more detail. Identify Engelman's syndrome can be anywhere from 3-7 years. Children have cramps, poor digestion, problems with coordination of movements. Most of them have strabismus and problems with facial muscles, which is why a smile is often on the face. The movements of the child are very constrained. For doctors, this is understandable when trying to walk a child. Parents in most cases do not know what is happening and especially with what it is connected. A little later, it is also noticeable that they can not speak, only try to mutter something inarticulate.

The reason why a child has a syndrome is a problem in the 15 chromosome. There is a very rare disease - 1 case for 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 the defeat of the central nervous system. The reason is the defeat of one gene in the 17 chromosome. As a result, nerve cells in the brain are destroyed with progressive rapidity.

Signs of the disease can be seen at 3 months old. Manifestation of Canavan is as follows:

1. Muscular hypotension.
2. Macrocephaly.
3. Seizures appear at the age of one month.
4. The child is not able to hold his head upright.
5. After 3 months, tendon reflexes increase.
6. Many children go blind by 2 years.

As we can see, hereditary human diseases are very diverse. The list given just for example is far from complete.

I would like to note that if both parents have a violation in the same gene, the chances of having a sick child are great, but if the anomalies in different genes, then you can not be afraid. It is known that in 60% of cases the chromosomal anomalies in the fetus lead to a miscarriage. But still 40% of these children are born and are struggling for their lives.