They are the great forgotten in medicine, but those who suffer and their families have them very present. And they should be a little more present in everyone. Rare diseases are those that have a low incidence in the population, affecting a very limited number of people.
The last day of February celebrates World Rare Disease Day, a day for raising awareness about infrequent pathologies and raising awareness about situations of lack of equity and injustice experienced by affected families, many of whom make themselves heard this day.
The campaign is carried out, among others, by the Spanish Federation of Rare Diseases (ERDF) in coordination with the European Organization for Rare Diseases (EURORDIS) and with the I Ibero-American Alliance for Rare Diseases (ALIBER).
For a disease to be considered as rare, the same criteria are not followed worldwide. For example, in Europe a disease that affects one in 2000 people is considered rare. In the United States, this defines a disorder or illness suffered by less than 200,000 people.
Although few people suffer from a rare disease in particular, there are many who are considered as such, in fact, according to the World Health Organization, there are about 7,000 global diseases that affect 7% of children and adults of all the world.
Rare diseases range from cystic fibrosis and hemophilia to Angelman syndrome, with an incidence of approximately one case per 15,000 inhabitants, to Opitz trigonocephaly syndrome, which is extremely rare, with one case per million inhabitants. For these diseases, the biggest problem is lack of funding to be investigated.
Eleven questions about rare diseases
On this day we wanted know a little more about rare diseases through some frequently asked questions and their answers, extracted from the Spanish Society of Pediatric Dentistry and especially dedicated to children and others referred to as the "orphan drugs" and also to a pioneer reference society for rare diseases and families of who suffer them
Is it true that there is a delay in diagnosis between 5 and 10 years?
Only about 250 unusual diseases have been assigned a code in the International Classification of Diseases (ICD) of the World Health Organization, which makes it even more difficult to approach. Sometimes they are little known diseases, but other times they are known, but because of their infrequency, in clinical practice they are not taken into account as the first diagnosis. As a consequence, if the disease is severe and rapidly evolving without treatment it can cause the death of a newborn, or the appearance of important sequelae.
Thanks to the neonatal screening test, cases that could go underdiagnosed for years or even throughout the patient's life are being diagnosed.
What symptoms can make parents suspect that their child has an ER?
In general, you have to think about them when the symptoms or an association of symptoms are not typical of any other disease or there is an unexplained association of symptoms. In childhood, it should be noted that many congenital metabolism errors occur with digestive and neurological symptoms, either chronically or with acute phases, for which the doctor is consulted.
From what age can an ER be detected?
Symptoms may be present from birth, even in fetal life.. But they can appear at any age, especially in the first two years of life. When you think about these diseases and look for them, they can be diagnosed, even in fetal life, although it is more difficult because the studies to be carried out in these periods are much more complex. On the other hand, it is true that, sometimes, the doctor knows that he is seeing a patient with ER (because there are similar family cases undiagnosed, or because there is an exam that suggests it).
What are the main problems faced by families of children with a rare disease?
Frustration, anguish, loneliness and feeling of isolation are very frequent. But also socioeconomic problems are added, and given the chronicity of the disease and unmet needs, such as: rehabilitation, physiotherapy, special orthopedic measures, special education, speech therapy, etc ... If medical procedures are diversified and a large number is needed of consultations, the repercussions on work are very serious. They require not only medical attention, but also psychological and social support, and often nutritional measures. The latter are absolutely essential in many congenital metabolism errors.
Who should parents of children with Rare Diseases turn to?
They should consult with their pediatricians and they will refer the suspected children to specialized centers, depending on the symptoms they have. Generally, researchers and referral centers with ER experts are used, but still an etiological diagnosis may not be reached.
What are the main novelties in the research of the ER?
In recent years, many advances are being made, emphasis is being placed on these diseases, seeking means to address them. Work is being done in many fields simultaneously: medical, social, research and in obtaining new treatments. Thanks to the improvement in laboratory techniques and the better knowledge of each disease, the number of diagnoses has increased and the development of new techniques, including mass spectrometry and high performance platforms for mutation analysis, has made it possible that more than 50 different genetic diseases can be detected in a single paper blood sample of the newborn.
With scientific advances, progress is made in the knowledge of diseases, with the aim of finding more effective treatments, which although they are not curative for certain diseases, do improve the quality of life of those affected.How many people affect RE?
If considered as a whole, they affect approximately 6 to 8% of the population. There are about three million affected in Spain and about 20 million in the EU. It is estimated that 2/3 of the total begin before two years of age, causing 35% of deaths during the first year of life, 10% between one and five years, and 12% between 5 and 15 years. It has been said that 1 / 4,000 children are born sick. An important fact that must be taken into account when talking about ER, is that a defect in a certain gene can cause different diseases or even give no symptoms, sometimes this defect causes different diseases.
What are the rare diseases that most affect children?
 Since the definition of a rare disease is based only on the frequency of a given disease, depending on how the data is obtained there is difficulty in knowing exactly the incidence of a disease or group of diseases due to a common cause. On the other hand, the international population migrations that currently exist contribute to modifying the prevalence.
In childhood, the most frequent genetic pathologies are thalassemias which are the most frequent hereditary diseases in the world with around 250 million people affected. In Spain, they affect between 0.2 and 2% of the population, but there are only about a hundred cases of thalassemia major.
Cystic fibrosis is also considered frequent for which a prevalence between 1 / 8,000 and 1 in 10,000 individuals in Europe had been estimated. However, studies of neonatal screening in Spain have shown a prevalence of 1 for every 3,449 newborns, higher than those reported for ER.
Within the family of congenital myopathies, the most serious Duchenne disease affects 1 per 3,300 births of men and Becker's disease, more infrequent, 1 for every 18,000 to 31,000 births of men.
Do ERs also affect babies after birth?
It is necessary to highlight the group of inborn errors of metabolism (EIM) that, taken one by one, are very rare but as a whole it is estimated that they affect between 1/500 to 1/800 live newborns. EIMs are a very large group of diseases that, thanks to the “expanded neonatal screening test” (ANC), can be diagnosed and treated early. Therefore, it is important to take them into account, as they are treatable causes, being able to make a prenatal diagnosis and administer genetic counseling.
What are "orphan drugs"?
Orphan drugs are those medicinal products intended for the diagnosis, prevention or treatment of life-threatening or very serious diseases or diseases that are rare. They are called "orphans" because the pharmaceutical industry has little interest, under normal market conditions, to develop and market products targeting only a small number of patients suffering from very rare conditions.
What is Orphanet?
Orphanet is an association created by experts in rare diseases and lawyer Ségolène Aymé in 1997 with the aim of establishing a free access database on rare diseases and medications to treat them. In 2000 Orphanet created an information portal on rare diseases and orphan drugs, and is also coordinating the Thematic Consultative Group on Rare Diseases of the World Health Organization, in charge of the revision of the International Classification of Diseases.
