Rare Diseases Research

About Rare Diseases

Rare diseases represent diseases health professionals are generally less knowledgeable about due to their infrequent occurrence, because they receive little focus in medical training programs and because they generally do not represent a viable market for commercial products, without specific incentives progressively being introduced. The definition of rarity differs from one region to another. The European Union considers diseases to be rare when they affect no more than 5 in 10,000 persons, the USA considers a disease to be rare if it affects fewer than 200,000 persons and some Asian countries have selected a threshold of 1 affected person in 10,000 .

While these diseases are rare, altogether patients are numerous as there are some 7,000 known rare diseases. Most rare diseases are genetic diseases, others are rare cancers, auto-immune diseases, congenital malformations, toxic and infectious diseases. While signs may be detected at birth or in childhood, over 50% of rare diseases appear during adulthood and are often life-threatening or chronically debilitating. Usually there is no effective treatment, but screening for early diagnosis, followed by suitable care, can improve quality of life and life expectancy.

The specificity of rare diseases – limited number of patients and scarcity of expertise – single them out as a distinctive domain where international collaboration has high added-value. Knowledge must be shared and resources combined as efficiently as possible to tackle rare diseases effectively as a whole. Historically, health authorities have not systematically considered rare diseases to be a public health issue and rare diseases have not been the focus of research programs due to a lack of data. Today, however, most European Union member states and a number of other countries have launched national plans on rare disease research and management.

A growing number of international initiatives are conducting projects to advance research and foster collaborative work to respond to the needs of rare disease patients. Typically, rare diseases have attracted little attention from the pharmaceutical industry due to their limited potential market. Many biotechnology and several pharmaceutical companies, however, are investing their efforts increasingly into developing therapeutic solutions to treat and manage rare diseases.


Research in Rare Diseases

Research into rare diseases (RD) is badly needed as many patients still lack a proper diagnosis and most of them are left without effective treatment. It is also an area where experts are rare as well.

However, research in this area is very relevant from a scientific point of view since RD studies may reveal physiological mechanisms and pathways as well as RD are model diseases for more common disorders and strong drivers of innovation: in 2011, 33% of marketed innovative medicinal products in the USA are intended for a rare disease. However research in this field faces some special constraints stemming in particular from the low prevalence that represents the defining characteristic of RD. Another major barrier is the sheer number of RD (an estimated 6,000 to 8,000 depending on the granularity of the disease definition) and their high phenotypic heterogeneity.

To attract interest from academic and Industry researchers, specific initiatives have been taken at country level, as early as 1983 in the USA, and at EU level in 1999 which proved successful in boosting the development of orphan drugs (OD), but there is still to date a very limited number of marketed orphan drugs, leaving a large majority of rare diseases without any effective treatment.

Increasing the number of diagnostic tests for patients suffering from RD requires accelerate the identification of yet unknown critical genes, to improve identification of genes defects. This is critical to increase knowledge of pathophysiology and natural history of RD, to identify potential therapeutic targets, discover new biomarkers, and define appropriate surrogate end-points to adequately evaluate treatments and therapies.

In order to translate research results into diagnostics and into the marketing of orphan drugs, it is essential that information, data and samples to boost research be shared internationally. Thus, an exhaustive RD classification, data repositories, standard terms of reference and common ontologies, as well as harmonized regulatory requirements need to be established at international level.

Click here to access the extended version of IRDiRC Policies & Guidelines.


State-of-Play of Research


IRDiRC analyses recent major research initiatives and outcomes and aims to identify the trends likely to shape the future of rare disease research. IRDiRC publishes an annual report on the State of Play of research, in order to inform stakeholders at large on developments in the field of rare diseases and support policy-makers and research funders in their decision making.

The State of Play report highlights the peer-reviewed literature that identifies trends and breakthroughs in research in the field of rare diseases. The report does not focus on initiatives to improve the organization of healthcare systems or on articles covering aspects of the orphan drug market, and trends and breakthroughs in genomics, and -omics in general, are not reported unless they bear specific rare disease features.

The annual State-of-Play report can be found here.