Rare Diseases: A Call to Arms for Coordinated, Global Research

Better definitions could lead to better diagnosis and treatment for rare diseases that collectively affect millions

Rare diseases are…rare, right? Not as rare as you might think. As much as 10% of the population is thought to have a rare disease, and a recent study found that the number of different rare diseases may be higher than previously estimated. The study, published in a recent commentary in Nature Reviews Drug Discovery, underscored the importance of agreeing on precise definitions of each rare disease so that they can be more accurately diagnosed and treated.

Thousands of rare diseases cumulatively affect millions of people across the globe, yet because each case is so rare doctors struggle to accurately diagnose and effectively treat individual patients. Every time a patient with an unspecified disorder walks into a clinic or shows up in an emergency room, doctors must start from scratch. “Most of these diseases they’ll never see again in their lifetime,” said lead author Melissa Haendel, Ph.D., associate professor of medical informatics and clinical epidemiology in the Oregon Clinical and Translational Research Institute (OCTRI). “If we can’t precisely define each rare disease, how can we diagnose and treat them?”

The authors of the article, an international team of data scientists and rare disease specialists, call for a coordinated effort to better define rare diseases. The scientists are bringing together separate efforts in rare disease research, and developing open-access computational tools to help experts come up with a precise definition for each rare disease. We call this unified, evolving set of disease definitions Mondo, from the Italian word for “world”, because it brings together information from all over the world.

Haendel wrote the commentary with 18 co-authors from the United States, Australia, France and Germany, including collaborators from the Monarch Initiative. In it, the authors call upon the World Health Organization, the U.S. Food and Drug Administration, the European Medicines Agencies, the National Academy of Medicine and other entities to adopt a unified definition of rare disease.

Commentary: Haendel M, Vasilevsky N, Unni D, Bologa C, Harris N, Rehm H, Hamosh A, Baynam G, Groza T, McMurry J, Dawkins H, Rath A, Thaxon C, Bocci G, Joachimiak MP, Köhler S, Robinson PN, Mungall C, Oprea TI. How many rare diseases are there? Nat Rev Drug Discov, 2019 Nov 5. https://www.nature.com/articles/d41573-019-00180-y

UNM press release: http://hscnews.unm.edu/news/how-many-rare-diseases-are-there

OHSU press release: https://blogs.ohsu.edu/researchnews/2019/11/21/scientists-suggest-new-solution-to-the-rare-disease-problem/