Generality
Rare diseases are diseases that, as can be guessed from the term "rare", affect a small number of people.
In Europe (therefore also in Italy), a disease is defined as rare, when it affects 1 in 2, 000 individuals, it is debilitating and has chronic or fatal consequences for the patient.
Currently, doctors have identified 7, 000-8, 000 rare diseases; this figure, however, is destined to grow.
The list of almost 8, 000 rare diseases includes, mainly, genetic diseases and, secondarily, infections, allergies, degenerative diseases and tumors.
Some known rare diseases are imperfect osteogenesis, Ehlers-Danlos syndrome, Duchenne muscular dystrophy, smallpox, amyotrophic lateral sclerosis and Morgellons syndrome.
What are Rare Diseases?
Rare diseases are all those diseases that affect a small percentage of the population .
With the expression "rare disease", therefore, the doctors indicate a not very common condition, of which only a few people worldwide suffer.
Definition of Rare Disease in the World
Currently, there is no single definition, accepted all over the world, to describe rare diseases. Some definitions, in fact, only consider the number of people suffering from a rare disease; other definitions, on the other hand, consider, in addition to the number of affected individuals, also other factors, such as the severity of the condition (if it is chronic, if it is debilitating, etc.) or the existence of adequate treatments.
For the States of Europe (therefore also for Italy), the definition describing rare diseases says that:
- Rare diseases are all those debilitating diseases, potentially lethal or chronic, affecting less than 1 in 2, 000 individuals.
Curiosity: definition of Rare Disease in other parts of the world
- In Japan, all the conditions affecting 1 in 2, 500 people are called rare diseases.
- In the United States, all those diseases affecting 1 in 1, 500 people take the wording of rare diseases.
Definition of Rare Disease in the Medical Area
In the medical literature, rare diseases are described as those diseases with a prevalence ranging from 1 case per 1, 000 people considered to be 1 case per 100, 000 people considered.
Prevalence means: number of cases present on a given population.
Features
- The list of rare diseases is composed, by 80%, of genetic diseases and, for the remaining 20%, of conditions such as infections, allergies, degenerative diseases (eg: neurodegenerative diseases) and proliferative diseases, better known like tumors ;
Rare diseases, therefore, are mostly pathologies resulting from the mutation of one or more genes;
- To date, the number of known rare diseases fluctuates between 7, 000 and 8, 000 ; however, it should be pointed out that this is a figure that continues to grow, as doctors have increasingly effective diagnostic techniques in recognizing conditions that are still unknown;
- As a rule, rare diseases are debilitating conditions with a chronic / permanent or fatal consequences ;
- Since the availability of adequate treatments is in the interest of a few patients, the medical-scientific community devotes little time and few economic resources to the search for new treatments against rare diseases known so far.
This is the main reason why those who suffer from a rare disease can hardly count on a therapy that has purposes other than mere "management" of the symptoms;
- When rare diseases are not the subject of scientific research and when adequate treatments do not exist for them, the experts define the aforementioned conditions with the term orphan diseases .
A disease is called an orphan when it is rare, when it does not raise particular scientific interests and, finally, when those affected do not have adequate treatment.
Epidemiology
According to the most recent estimates, in the world, individuals suffering from a rare disease would be more than 300 million and, in 70-75% of cases, they would be pediatric subjects (in other words, they would be children).
In Italy, estimates of the number of people with a rare disease speak of 1-2 million affected individuals, while those relating to the percentage of pediatric patients report that the latter represent about 70% of all carriers of a rare disease.
Did you know that ...
Statistics show that every 17 individuals there is one that, at a certain stage of its existence, will develop a disease that is included in the list of rare diseases.
Related to the number of inhabitants in Europe, one clinical case per 17 people corresponds to 7% of the total population.
Interesting data and other statistics on Rare Diseases
- In the United States, about 30 million people suffer from a rare disease; in the USA, 30 million individuals are equivalent to 10% of the total population;
- As in the United States, even in Europe the subjects suffering from a rare disease are around 30 million;
- 30% of children with a rare disease die within the fifth year of life;
- Rare diseases are responsible for 35% of deaths within the first year of life;
- According to the Kakkis EveryLife Foundation, 95% of rare diseases do not have a single drug approved by the FDA (US government agency for the regulation of food and pharmaceuticals);
- About 50% of known rare diseases do not have a foundation aimed at finding adequate treatments.
Causes
The causes of rare diseases include:
- Genetic mutations . A genetic mutation is a stable change in the characteristic DNA sequence that constitutes a certain gene.
Genetic mutations are at the origin of most rare diseases.
Examples of genetic diseases, rare diseases due to a genetic mutation are congenital conditions, ie present since birth;
- Chromosomal alterations . A chromosomal alteration is a stable anomaly affecting a certain chromosome; located within the cell nucleus, chromosomes are the particular structures into which the entire DNA is divided.
Since chromosomes contain several genes, chromosomal alterations are responsible for changes in the sequence of multiple genes.
Just like rare diseases due to a genetic mutation, even rare diseases resulting from a chromosomal alteration are congenital conditions belonging to the great category of genetic pathologies.
- Infectious agents . Infectious agents that cause rare diseases include bacteria, viruses, fungi and parasites.
Rare diseases due to the action of an infectious agent are examples of rare infections .
- Allergic reactions . Rare diseases resulting from an allergic reaction are examples of rare allergies .
- Degenerative processes . In degenerative processes, we are witnessing the loss by a certain organ or tissue of normal anatomy / histology.
Rare diseases due to the degeneration of a certain organ or tissue are examples of rare degenerative diseases .
- Proliferative neoplastic processes . The neoplastic proliferative processes are events in which there is the excessive and uncontrolled growth of the cells belonging to a certain tissue or organ.
Rare diseases due to the uncontrolled proliferation of a certain cell line are examples of rare tumors .
Symptoms
In general, rare diseases are conditions that are characterized by a wide variety of symptoms and signs, which often causes carriers of the same disease to exhibit sometimes very different disorders.
Some rare diseases are pathologies that make their appearance at birth and in the first years of life; other rare diseases, however, appear only in adulthood. The mode of appearance of a rare disease basically depends on the causes.
Important examples
Some of the best known rare diseases are: Ehlers-Danlos syndrome, progeria, Morgellons syndrome, smallpox, Duchenne muscular dystrophy, cleft palate, hemophilia, leprosy (or Hansen's disease), fibrodysplasia progressive ossifying, imperfect osteogenesis, tongue tumor, neurofibromatosis, legionellosis, Angelman syndrome, trisomy 13 (or Patau syndrome), allergic angioitis (or eosinophilic granulomatosis with polyangioitis) and amyotrophic lateral sclerosis (or SLA).
Imperfect Osteogenesis
Imperfect osteogenesis is an example of a rare disease due to a genetic mutation.
Imperfect osteogenesis is the medical term that indicates a group of genetic diseases responsible for a certain bone fragility and a marked tendency to fracture.
To cause the condition of imperfect osteogenesis are mutations against genes that control the production of collagen (a protein essential for bone health) or other proteins essential to guarantee strength and resistance to the skeletal apparatus of the human being.
The group of diseases under the heading "imperfect osteogenesis" includes more serious conditions than others.
Imperfect osteogenesis is included in the list of rare diseases, because it affects a new born every 15, 000 to 20, 000.
Allergic Angioite
Allergic angioitis is an example of a rare disease due to an allergic reaction.
Allergic angioitis is a vasculitis of the vessels of small or medium size, which mainly affects the respiratory tract (lungs in particular) and begins in a similar way to an allergy (when the disease is in its infancy, patients experience episodes of asthma and allergic rhinitis).
Allergic angioitis can have fatal consequences; in fact, at the most advanced stages, it may concern the vessels that supply the heart and compromise the health of the latter.
Allergic angioitis is included in the list of rare diseases, as 1-9 people suffer per 100, 000.
Tongue tumor
Tongue cancer is an example of a rare disease due to an abnormal neoplastic proliferative process.
Tongue cancer is the result of a neoplastic proliferative process, which starts from one of the cells that make up the tissues of the tongue.
Currently, it is not clear whether tongue cancer depends on a specific cause; however, doctors and scientists believe that factors such as tobacco consumption, alcohol abuse, poor oral hygiene and continuous exposure to fumes, dust and toxic substances play a decisive role in the onset of the disease in question. .
Tongue cancer is a condition whose prognosis depends on at least three factors: timeliness of the diagnosis, location of the neoplastic mass and general state of health of the patient.
Tongue cancer is included in the list of rare diseases, as in Europe it has an annual incidence of 8-10 cases per 100, 000 people considered.
Smallpox
Smallpox is an example of a rare disease due to an infectious agent.
Smallpox is a highly contagious and highly lethal infectious disease, the result of the action of the virus known as Variola major .
Smallpox is responsible for a characteristic vesicle-pustular rash (or rash), accompanied by a profound impairment of general health.
Smallpox is included in the list of rare diseases, as it is now an infection eradicated for several decades. The last case of known smallpox, in fact, dates back to 1977.
SLA
Amyotrophic lateral sclerosis is an example of a rare disease due to a degenerative process affecting an organ or tissue of the human body.
Known not only as ALS but also as Gehrig's disease or motor neuron disease, amyotrophic lateral sclerosis is a neurodegenerative disease characterized by the progressive deterioration of the motor neurons of the central nervous system.
Since faculties such as breathing, swallowing, walking, talking, holding objects, etc. depend on motoneurons in the central nervous system, ALS is a highly debilitating condition for those suffering from it; in fact, it forces those who hit the wheel chair to breathe through a support for mechanical ventilation, to feed themselves through a tube etc.
Amyotrophic lateral sclerosis is a very serious disease, which has always been fatal over a period of time ranging from 3 to 5 years.
Despite numerous scientific research on the subject, the precise causes of amyotrophic lateral sclerosis are unknown.
ALS is one of the so-called rare diseases, as it affects 1-2 people every 100, 000 annually.
Trisomy 13
Trisomy 13 is an example of a rare disease due to a chromosomal alteration.
Trisomy 13 is an anomaly of genetic heritage (and therefore of DNA), characterized by the presence at cellular level of 3 copies of chromosome 13 (NB: in the absence of anomalies, human chromosomes are organized in pairs). In individuals suffering from trisomy 13, therefore, the chromosome set is 47 chromosomes instead of 46 (22 pairs of non-sexual chromosomes and a couple of sex chromosomes).
Currently, the cause capable of altering the copy number of chromosome 13 is unknown; the only certainty is that the chromosomal alteration can occur both before and after the meeting between the egg cell and the spermatozoon.
Trisomy 13 is a very serious rare disease, which in general determines the death of the affected subject even before birth or during the first 7 days following the birth.
Trisomy 13 is one of the rare diseases because it affects a new born every 8, 000-12, 000.
