Hereditary diseases are those diseases that are transmitted through germ cells from generation to generation. In total, there are more than six thousand diseases of this type. About a thousand of them today can be identified even before the birth of a child. Also, these diseases can manifest themselves at the end of the second decade of life, and even after 40 years. Mutations in genes or chromosomes are the main cause of hereditary diseases.
Classification of hereditary diseases
Hereditary diseases are divided into two groups:
- Single causal or monofactorial. These are diseases that are associated with mutations in chromosomes or genes.
- Multi-causal or multifactorial. These are diseases that appear as a result of changes in various genes and due to the influence of numerous environmental factors.
For the appearance of a similar disease in one of the family members, this person must have a similar or the same combination of genes that his close relatives already have. That is why hereditary diseases are associated with the presence of common genes in relatives of varying degrees of kinship.
Degree of relatedness and share of common related genes
Since each first-degree relative of the patient has 50% of his genes, therefore, these people can have an identical combination of genes that predisposes to the appearance of this disease. Relatives of the third and second degree of kinship are slightly less likely to have the same set of genes with the patient.
Hereditary diseases - types
Hereditary disease can have more than one kind. Distinguish:
- Chromosomal diseases. Often, when a cell divides, it happens that individual pairs of chromosomes remain together. As a result, the number of chromosomes in a new cell is greater than in others. This fact leads to metabolic disorders. These diseases occur in 1 out of 180 newborns. These children have numerous congenital malformations, mental retardation and more.
- Autosome disorders lead to multiple and serious ailments.
- Gene mutations. Monogenic diseases involve mutations in one gene. These diseases are inherited according to Mendel's law.
- Hereditary metabolic diseases. Almost all gene pathology is associated with hereditary metabolic diseases. When a mutation occurs in the process of operon structure, a protein with an irregular structure is synthesized. As a result, pathological metabolic products accumulate, which is very harmful to the brain.
There are other hereditary diseases. Before starting theirtreatment, it is necessary to undergo a complete diagnosis. Doctors recommend to be extremely attentive to all expectant mothers in whose family there are patients with this diagnosis. This is because such pregnant women should be under special supervision. Only in this case, the degree of manifestation of this disease in the baby can be minimized. The main thing to remember is that any hereditary disease, with medical intervention at a certain right period of time, can proceed much easier.
