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Defining rare conditions in the era of personalized medicine

The total number of rare conditions is debated, partly because of the variety of definitions of what constitutes rare. A broader consensus view of what rare means, based on improved understanding of individual group and patient clinicopathological characteristics, will help maximize the impact of technological advances in therapeutic development programmes.
  1. Daniel J. O’Connor

    1. Therapies Scientific Committee, International Rare Disease Research Consortium, Paris, France; The Association of the British Pharmaceutical Industry, London, UK.

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  2. Michela Gabaldo

    1. Therapies Scientific Committee, International Rare Disease Research Consortium, Paris, France; Aptuit, an Evotec company, Verona, Italy.

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  3. Annemieke Aartsma-Rus

    1. Therapies Scientific Committee, International Rare Disease Research Consortium, Paris, France; Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands; Dutch Center for RNA Therapeutics, Leiden, the Netherlands.

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  4. Anneliene Hechtelt Jonker

    1. Therapies Scientific Committee, International Rare Disease Research Consortium, Paris, France; University of Twente, Enschede, the Netherlands.

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Rare conditions have been defined and categorized in a variety of ways. Traditionally, rare conditions have been described with specific clinical features and in some cases named after their discoverer. Through a panel of experts and in collaboration with the World Health Organization, an operational description of rare diseases has been proposed by Rare Diseases International: a medical condition with a specific pattern of clinical signs, symptoms and findings that affects fewer than or equal to 1 in 2,000 persons living in any World Health Organization-defined region of the world. Numerous other similar and overlapping definitions exist, including those from regulatory authorities, governments, not-for-profit organizations and patients’ organizations1. In these definitions, it is generally accepted that rare diseases are defined by their low prevalence, that patients with rare diseases face specific challenges in their diagnostic and treatment journeys, and that these patients should have the same opportunities for health care as patients with more common conditions.

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Nature Reviews Drug Discovery 22, 857-858 (2023)

doi: https://doi.org/10.1038/d41573-023-00145-2

References

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Competing Interests

A.A.-R. discloses being employed by LUMC, which has patents on exon skipping technology, some of which have been licensed to BioMarin and subsequently sublicensed to Sarepta. As co-inventor of some of these patents, A.A.-R. is entitled to a share of royalties. A.A.-R. further discloses being an ad hoc consultant for PTC Therapeutics, Sarepta Therapeutics, Regenxbio, Dyne Therapeutics, Lilly, BioMarin Pharmaceuticals., Eisai, Entrada, Takeda, Splicesense, Galapagos and AstraZeneca. Past ad hoc consulting has occurred for Alpha Anomeric, CRISPR Therapeutics, Summit, Audentes Santhera, Bridge Bio, Global Guidepoint and GLG consultancy, Grunenthal, Wave and BioClinica. A.A.-R. also reports having been a member of the Duchenne Network Steering Committee (BioMarin) and being a member of the scientific advisory boards of Eisai, Hybridize Therapeutics, Silence Therapeutics and Sarepta Therapeutics, and a past member of the scientific advisory boards for ProQR and Philae Pharmaceuticals. Remuneration for these activities is paid to LUMC. LUMC also received speaker honoraria from PTC Therapeutics, Alnylam Netherlands, Pfizer and BioMarin Pharmaceuticals and funding for contract research from Italfarmaco, Sapreme, Eisai, Galapagos, Synnaffix and Alpha Anomeric. Project funding is received from Sarepta Therapeutics and Entrada. The other authors declare no competing interests. The views of the authors are their own and do not necessarily reflect their respective affiliations

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