Paris - The number of rare diseases is rising steadily as result of improved genetic diagnostics. The Orphanet already records more than 6,100 diseases with frequency of less than 5 in 10,000 people, from which, according to an analysis by Orphanet in the European Journal of Human Genetics (2019; doi:), around 20 million people in Europe and 300 million people worldwide suffer.
The Orphanet was started in 1997 at one of the French national research institutes ("Institut national de la santé et de la recherche", Inserm). It has been supported by the European Commission since 2000. Today researchers from 40 countries also from outside Europe participate in the cataloging of rare diseases.
The rarity of disease is ultimately question of definition. The Orphanet currently draws the line at point prevalence of 5 to 10,000 people. By October 1, 2018, the cut-off date for the analysis by Stéphanie Nguenguan from Inserm US14 in Paris, 6,172 diseases had been recorded. A total of 3,510 (69.9%) always lead to symptoms in childhood. Another 908 (18.2%) begin either in childhood or in adulthood. Only 600 (11.9%) occur exclusively in adult patients. The early onset is usually the result of genetic disease, which is assumed for 4,440 rare diseases (71.9%).
Not all diseases have information on the frequency. In addition, the list is far from over. Nguenguan's calculations are therefore only first approximation. The global point prevalence could be between 3,482.3 and 5,910.3 per 100,000 population. This means that 3.5 to 5.9% of the general population would suffer from rare diseases which, taken together, could no longer be described as rare. According to Nguenguan, 17.8 to 30.3 million people could be affected in the European Union, and between 262.9 and 446.2 million worldwide.