The European Union and United Kingdom define a disease as rare if it affects fewer than 1 in 2,000 people, but there is no universal definition. Each country has its own definition of how prevalent rare diseases are amongst its population. What we do know is that rare conditions can evade detection for years.
Rare diseases present a wide variety of symptoms, which often appear unrelated on the surface. Rare medical conditions can touch a person’s life at any moment; during childhood, adulthood or both. Rare disorders, as they are sometimes called, can affect a single system in the body or multiple organs. Rare disease symptoms and their impact on patients are as diverse as the diseases themselves.
How many rare diseases are there in the world?
- 69.9% (3,510 rare diseases)are exclusively paediatric onset
- 11.9% (600 rare diseases) are exclusively adult onset
- 18.2% (908 rare diseases) have onset spanning both paediatric and adult groups
The RARECARE European population-based rare cancer registry data estimates that 4,300,000 people are living with a rare cancer diagnosis in the European Union alone. This accounts for 24% of all cancer diagnoses in the EU.
Global rare disease prevalence: they are more common than you think!
Globally, rare diseases affect between 3.5% and 5.9% of the population. This means that anywhere between 263 million and 446 million people are living with a rare disease in the world. Wakap et al. (2020).
Go around the world to discover the most up-to-date definitions of how many people are affected by rare disease in each country.
European Union (EU) and UK definition
Affects fewer than 1 in 2,000 people
Affects fewer than 1 in 2,000
Affects fewer than 1 in 1,316
Affects fewer than 1 in 2,500
Affects fewer than 65 out of 100,000 individuals (1 in 1,538 people)
Affects fewer than 1 in 1,250 people
Rare cancers in the EU
Affects fewer than 108 in 100,000
Affects 1 in 12 Canadians. Approximately 3 million Canadians and their families have a rare disease.
Affects fewer than 1 in 10,000
Affects 72,611,605 people
What are examples of rare diseases?
For a comprehensive list of the known rare diseases, please see the following databases:
- Orphanet Database for Rare Diseases and Orphan Drugs
- National Organization for Rare Disorders (NORD) Rare Disease Database
Rare diseases are classified and understood as either genetic or non-genetic in nature. If a rare condition is not genetic in nature, then the cause will be environmental in some way.
The condition could have been triggered by a bacterial or viral infection, an allergen or other environmental factors, such as breathing in asbestos. Some rare medical conditions remain unexplained.
What is a genetic condition?
A genetic condition is one that is caused by an error or mutation in a person’s DNA. The errors in a person’s genes cause proteins to be built incorrectly. When the proteins are built incorrectly, a change in the way the body functions results. This change causes the symptoms of a rare disease.
A genetic disorder, as it is sometimes referred to, can be caused in the following four ways, according to the National Human Genome Research Institute:
- A mutation on one gene (Monogenic)
- A mutation on multiple genes (Multifactorial inheritance)
- A combination of gene mutations and environmental factors
- Structural damage to chromosomes
Most genetic conditions are heritable, which means that they have been passed down from parents to their children. Some genetic conditions are caused by completely new mutations that arise in an individual. These are called spontaneous mutations, which can occur in an egg, sperm or developing embryo.
Did you know?
72% of all rare diseases are genetic in nature, of which 80% are inherited.
What are the most common rare diseases?
Some of the most well-known rare diseases are:
- Ehlers –Danlos Syndrome (EDS)
- Sickle Cell
- Cystic Fibrosis
- Duchenne Muscular Dystrophy (DMD)
You have probably heard about these in the media or know someone who has been affected by the disease. These diseases are in fact rare, but they receive the most awareness, funding and research in comparison to very rare and ultra-rare diseases.
Rare conditions are all around you. You just may have never known!
How many rare diseases have treatment?
There isn’t a consensus on how many rare diseases have treatment. Because the number is so hard to pinpoint, rare disease stakeholders say that roughly 95% of rare conditions do not have a treatment. This means that only 5% of rare conditions have a licensed treatment.
At Beacon, we are working to change this. We believe that the key to advancing rare disease treatment is through drug repurposing.
What rare diseases all have in common
There is a common thread that connects all rare disease patients and families. Medical understanding, knowledge and research of rare diseases are limited. Patients and their families often fall victim to misdiagnosis, delayed treatment, poor care coordination and a lack of support. Having a rare disease can be an isolating experience not only for the patient, but also his or her family. Rare conditions and those they affect should not be overlooked by doctors and researchers.
At Beacon, we want to see the day when no one is handed a Google printout and is simply told to go home and deal with it.