DNA controls the functions, behaviour and structure of each cell, it has the ability to reproduce and produce a copy of itself.
DNA is made up of a sequence of 4 elementary molecules, the nucleotides: A (adenine), T (thymine), C (cytosine), G (guanine).
It is the precise order of these four letters within the DNA molecule that constitutes the genetic information.
In humans, it includes three billion letters.
Unfortunately, it sometimes happens that there are "writing errors", that the information blocks following an alteration of the genome, this can lead to a rare genetic disease.
A genetic disease is a disease due to one (or more) anomaly(ies) on a chromosome or on a gene leading to a malfunction of certain cells in the body.
This alteration causes the cell to malfunction, which can be revealed, at any age of life, with the expression of a disease.
Genetic diseases are said to be dominant or recessive, if the allele responsible is dominant or not (in an individual each gene is represented by two alleles).
Thus, there are genetic diseases transmitted by parents who do not suffer from them themselves.
Genetics allows the deciphering of DNA and its sequencing.
This decoding of the human genome opens a better sharing of knowledge and a better understanding of diseases.
Indeed, knowing that such and such a "writing error" in a gene is at the origin of such and such a disease makes it possible to identify its cause.
Among genetic diseases, we find benign or slightly disabling conditions as well as extremely serious ones.
But their common characteristic is generally to be a lifelong condition and that can in some cases be transmitted to descendants, since it is written in the genes.
The so-called rare diseases are characterized by a wide variety of clinical signs that vary not only from one disease to another but also from one patient to another with the same disease.
Rare diseases are those that affect a limited number of people and therefore pose specific problems related to this rarity.
They are sometimes serious, generally chronic, sometimes progressive, and the vital condition may sometimes be at stake.
Specific treatments are rare.
Some cases are too particular to be the subject of significant research, or there are simply no research teams for these deficits...
Fortunately, things are beginning to change thanks to the mobilization of associations, researchers, and centres of reference for rare diseases coordinated by specialized networks in France and in Europe.
Many orphan drugs are beginning to appear.
Genetic research is providing solutions by diagnosing and identifying new therapy techniques...
It is opening up new perspectives for the care of patients.
At the same time, we must salute the daily work of the many patient associations that are fighting to make the disease better known to the general public, as well as the medical and paramedical professionals who care for patients day and night.
6,000 to 8,000 rare diseases are counted.
5 new diseases are described each month in the medical literature.
About 80% of rare diseases have a genetic origin.
There are also rare infectious diseases as well as autoimmune diseases, but for a large number of diseases, the origin remains unknown to this day.
1 person in 20 would be concerned
3 out of 4 diseases are paediatric diseases generating severe disabilities.
Some diseases may wait 30, 40 or 50 years before appearing.
Rare diseases affect nearly 3 million people in France and 30 million in Europe.
Certain hereditary genetic diseases increase the risk of massive myolysis.
Among them we can mention:
Deficits in mitochondrial oxidation of fatty acids
Mutations in the RYR1 gene