Most rare diseases are of genetic origin

The lack of reliable data hinders real understanding

The term “rare disease” – and February 28 is World Rare Disease Day – speaks for itself: they are diseases that affect a few people in a population. The classification refers to diseases that occur at a frequency of 1.3 or less per 2,000 people, as defined by the World Health Organization.

Though rare, there are a variety of diseases that fall under the definition, ranging from 6,000 to 8,000 types. “As new diagnostic methods are developed, more varieties are identified,” says Magda Carneiro Sampaio, professor of Clinical Pediatrics at the Faculty of Medicine of the University of São Paulo. Multiple sclerosis, Guillain-Barré syndrome, cystic fibrosis and congenital hypothyroidism are among the best known rare diseases. The concept of rare disease may vary according to its frequency in different regions. For example, dengue can be considered rare in European countries.

But most of these diseases are considered rare anywhere in the world. Approximately 70% appear in childhood and 80% have a genetic origin, i.e. are caused by mutations or changes in the genes. The remaining 20% ​​of diseases arise from other causes, such as infectious diseases. But not all genetic diseases are rare. This is the case with Down syndrome, which occurs in 1 in 700 births. In Brazil it reaches, according to estimates, 13 million people.

Many of the general numbers on rare diseases circulating in Brazil are based on estimated inferences from data from other countries. “We don’t even know for sure the extent of the problem,” says Salmo Raskin, president of the Scientific Department of Genetics at the Brazilian Society of Pediatrics.

Scenario that could change in the coming years, among other things, due to the ongoing work carried out by members of the National Network of Rare Diseases (raras.org.br). This research project led by the Hospital de Clínicas de Porto Alegre, of the Federal University of Rio Grande do Sul, will collect real data on rare diseases in Brazil. The survey is expected to conclude in 2025.

In terms of clinical manifestations, rare diseases are also characterized by diversity. They can affect the functioning of several physiological systems, such as the nervous, immune, cardiovascular and gastrointestinal tracts. Other characteristics already consolidated by clinical research: rare diseases are chronic and progressive and can lead to consequences such as developmental delays, physical and intellectual disabilities, malformations and even death.

A small number of diseases, between three and four dozen, have some type of specific treatment. But the development of rehabilitative therapies to control and reduce sequelae, and to improve the general quality of life of patients, can help a wide range of people affected by the most varied pathologies.

The second major difficulty for patients with rare diseases is the difficult access to rehabilitation services, which have professionals such as physiotherapists, speech therapists, nutritionists, psychologists and occupational therapists. The offer of this type of service is more concentrated in the South and South-East regions and in the Brazilian capitals. Abroad, other countries are also going through the same challenges as Brazil, maintaining due proportions. “Even small and rich countries, such as Switzerland, cannot deal with all cases,” says Magda Carneiro Sampaio.

Ordinance 199 of the Ministry of Health, published in 2014, can be considered a watershed in the field of rare diseases. Since then there have been positive developments in the sector. “One of the changes has been the inclusion of specific tests in the SUS,” explains Temis Maria Félix, geneticist at the Hospital de Clínicas of Porto Alegre and coordinator of the National Network of Rare Diseases.

In the last five years, legislation has introduced the National Policy for Integrated Care for People with Rare Diseases and enabled referral services. “The 20 reference care centers are not yet meeting all the demand and need to be expanded, but patient care has improved a lot,” says the geneticist from Porto Alegre.

Source: Terra

Ben

Ben Stock is a lifestyle journalist and author at Gossipify. He writes about topics such as health, wellness, travel, food and home decor. He provides practical advice and inspiration to improve well-being, keeps readers up to date with latest lifestyle news and trends, known for his engaging writing style, in-depth analysis and unique perspectives.