What Is a Rare Disease?
The definition of a rare disease differs by region. In the US, a rare disease is defined as a disease or condition that impacts fewer than 200,000 people.1 However, in the European Union and UK, a rare disease is one that affects no more than 1 in 2,000 people.2,3 In other regions such as Japan and Taiwan, this varies between 1 in 2,500 and 1 in 10,000, respectively.4
How Many Rare Diseases Are There?
There are currently ~7,000 rare diseases, currently affecting at any point in time 3.5–5.9% of the global population.5,6,7 This percentage is equivalent to ~300 million people worldwide (~30 million people in the European Union).2,5,6,7 Examples of conditions that are designated rare diseases include multiple sclerosis (90 people per 100,000), narcolepsy (50 people per 100,000), primary biliary cholangitis (40 people in 100,000) and cystic fibrosis (25 people per 100,000).4 Of the ~7,000 rare diseases, 72% are genetic.5,6,7 Other causes are disordered immunity, infections, allergies, deterioration of body tissues and organs, or disruption to development while in the womb.3
Rare diseases can be life-threatening as well as life-limiting. Furthermore, they disproportionately affect children, with 70% of rare diseases starting in childhood.3,5,6 Currently, 75% of rare diseases affect children, and more than 30% of children with a rare disease die before their fifth birthday.3
The Effects of Rare Diseases
Owing to their limited prevalence, treating these conditions can be a challenge as a result of the lack of knowledge around the disease area, scarcity of expertise and their chronic, degenerative and potentially life-threatening nature.5
The gap in knowledge comes at a price—many rare diseases have constrained options for treatment. Drugs for rare diseases are often commercially underdeveloped, as their limited end-market usage means they are not usually profitable enough for traditional research.4 Thus, therapies for rare diseases are also commonly known as ‘orphan drugs’, which are treatments that are not developed by the pharmaceutical industry for economic reasons but respond to public health need.8 The number of rare diseases for which no treatment is currently available is estimated to be between 4,000 and 5,000 worldwide.8
Additionally, relatively common symptoms can hide underlying rare diseases, leading to misdiagnosis and treatment delays.7 Symptoms can also differ not only from disease to disease but also from patient to patient suffering from the same disease.
Patient quality of life is affected by the lack (or loss) of autonomy owing to the chronic, progressive, degenerative and frequently life-threatening aspects of the disease.7 Patients with rare diseases and their family can face a long duration of complex care, and living with a rare disease can also have adverse effects on one’s education, financial stability, mobility and mental health.3 It is therefore important that the voice of rare disease patients is included when developing wider policy.3 Furthermore, research into rare diseases needs to be international to ensure that experts, researchers and clinicians are connected.7
Conclusion
At TVF, we have significant expertise in rare diseases. This puts us in a prime position to aid in the investigation, development, branding and marketing of potential therapeutics in the field of many rare diseases. If you would like to find out more about TVF’s business offerings, get in touch!
By Will Shieu
