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Rare Disease: How Common is the Uncommon?


What defines a rare disease?
In the United States, a rare disease is defined as any disease affecting fewer than 200,000 individuals; however, this definition varies by country.

How many people are affected by rare diseases?
There are approximately 30 million people in the United States who are living with a rare disease – a number that translates into 1 in 10 people. Globally, 350 million people are afflicted with a rare disease, the vast majority of which are children.

How many types of rare diseases are there?
There are 7,000 known rare diseases with new ones being discovered every year.

Are rare diseases acquired or genetic?
The majority of rare diseases – approximately 80 percent – are genetic and are typically present throughout one’s lifetime, even if symptoms do not immediately appear.

Why is rare disease often referred to as an “orphan” disease?
Orphan or rare diseases are not commonly pursued by the pharmaceutical industry. With rare diseases affecting such a small portion of the population, there is little financial incentive to create and market new medications.

How many treatments are available for rare disease?
Treatments are available for about 5 percent of all rare diseases. In response to the lack of interest by the pharmaceutical industry to conduct rare disease research, the Food and Drug Administration (FDA) established the Office of Orphan Products Development (OOPD) to offer grants and other incentives to pharmaceutical companies for research.

What challenges do rare disease researchers face?
Researchers involved in rare disease studies primarily run into challenges with the funding of clinical trials to further research advancements as they relate to rare disease, as well as recruiting a substantial pool of participants for clinical trials. Investigators facilitating clinical trials for non-rare diseases recruit participants through clinical trial registries – an online platform allowing individuals interested in participating in a clinical trial to submit their personal information. Investigators can then access the registry as it relates to the rare disease in which they are studying and recruit interested participants based on the information they submitted to the registry.



The views expressed in this content represent the perspective and opinions of the author and may or may not represent the position of Indiana University School of Medicine.
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