Rare or orphan diseases

What is a rare or orphan disease?

A rare disease is a disease that affects less than 1 in 2,000 people in the population

A rare disease is a disease that has a low frequency in the population. The most common definition of a rare disease is: a disease that affects fewer than 1 in 2,000 people in a population (in the United States, it is defined as a disease that affects fewer than 200,000 people in the population). Examples of rare diseases: cystic fibrosis, Duchenne muscular dystrophy, Huntington’s disease, autoimmune myasthenia gravis, Angelman syndrome, Ewing’s sarcoma, borreliosis, etc. More than 7,000 rare diseases have been identified worldwide. According to some estimates, these represent 25% to 35% of all human diseases. See below the definition of an orphan disease.

More than 7,000 rare diseases

Depending on the source, it is said that there are between 6,000 and 8,000 rare diseases. It depends on the databases that list them and the definition of a disease. New diseases are characterized regularly, especially thanks to genomic technologies. In 2023, theOrphanetportal lists more than 6,000 rare diseases and OMIM (Online Mendelian Inheritance in Man) lists about 7,000 diseases (only those of genetic origin). Since the year 2000, efforts in analysing various databases and the inclusion of diseases identified by the new genomic technologies have resulted in a an estimate of about 10,000 rare diseases. (Estimating the number of rare diseases – the concept of rare, ultra-rare and hyper-rare, 2022)).

 

40% to 50% of sick individuals do not have a diagnosis

A rare disease can be a disease that does not have a name. An individual may suffer from an illness that doctors cannot identify. In general, an undiagnosed disease is a rare disease. It is said that at any given moment, about 40% to 50% of individuals suffer from an illness do not have a diagnosis. Some will eventually get their diagnosis, but others may not get one in their lifetime. (Read this article: Les plus orphellines des maladies: les maladies sans nom)

Approximately 700,000 Quebecers are affected by or are carriers of a rare disease

Since the population of Quebec is approximately 8.8 million inhabitants (2023), this means that according to the definition above, a given rare disease is a disease that affects less than 4,400 people in the Quebec population. This number (4,400) represents the maximum for a rare disease, but the vast majority of rare diseases have a frequency of less than 1/100,000 people in the population (less than 44 individuals in Quebec would have a rare disease of this frequency).

There is no accurate count of the number of people with rare diseases worldwide. Depending on the country and the organization, the estimate given is 1/10 to 1/20 people in the population. In France, Orphanet estimates it at 1/20 (5% of the population). Le Canadian Organization for Rare Disorders (CORD) l’estime à environ 1/12 (environ 3,3 millions de personnes). The Quebec Ministry of Health estimates that approximately 700, 000 Quebecers are affected by or are carriers of a rare disease (source: Politique québécoise pour les maladies rares, MSSS, 2022; only in French).

More than 300,000,000 people are affected worldwide.

Nearly 75% of these diseases affect children

They can appear at any time in life: from conception, during in utero life, after birth, during childhood, adolescence or adulthood. Almost 75% of these diseases affect children and 30% of them die before the age of 5 years.

80% of rare diseases are of genetic origin

About 80% of rare diseases are genetic in origin.

Other types of rare diseases include cancers, autoimmune or inflammatory diseases, infections, poisonings, etc.

Rare diseases are very diverse in their presentation: acute diseases, chronic diseases, complex syndromes with or without malformations, diseases with progressive evolution, severe and fatal diseases, recurrent or episodic diseases, unpredictable diseases, diseases with physical disabilities, diseases with intellectual disabilities, diseases with physical and intellectual disabilities, diseases with “invisible” disabilities (e.g., immunodeficiency, pain, fatigue) and conditions affecting physical appearance.

What is an orphan disease?

The term “orphan” appeared in the early 1980s in the United States in connection with the treatment of rare diseases. Thus, a disease was said to be orphan if there was no treatment for the disease other than treating the symptoms. Companies or researchers were reluctant to develop a drug for a rare disease because it was not financially profitable.

Only about 5% of rare diseases have a specific treatment

In 1983, the United States introduced the Orphan Drug Act. Forty years after its application, the Food and Drug Administration estimated that it had approved drugs for only about 5% of rare diseases (A comprehensive study of the rare diseases and conditions targeted by orphan drug designations and approvals over the forty years of the Orphan Drug Act, 2023).

The term “orphan disease” has been generalized and often the terms “rare disease” and “orphan disease” are confused, because the vast majority of rare diseases are orphan diseases in many ways: lack of knowledge about the disease, difficulty in diagnosing it, little information on medical care, little or no research and no treatment.

We can say that many rare diseases are orphan diseases, because they are little known by the population and the medical community, they are the subject of little research and they result in a feeling of being left behind by the person who are affected and by their family.

A rare disease may be orphan in terms of diagnosis, research, treatment, care, etc. Those who suffer from a rare disease feel alone.

There are many different rare diseases, but those who are affected share common difficulties.

The rarity of these diseases creates particular barriers and needs for those affected, both in our health care system and in society at large:

  1. Delays in diagnosis
  2. Lack of information
  3. Lack of coordinated and appropriate quality care
  4. Presence of physical, mental, behavioral and/or sensory deficiencies, resulting in absence or loss of autonomy.
  5. Social consequences: living with a rare disease has an impact on studies, work, leisure, personal relationships, etc. There may be isolation, stigma, social exclusion and discrimination.
  6. Psychosocial burden for the entire family: the suffering of those affected and their families is often compounded by psychological despair and a lack of therapeutic hope.
  7. Difficulties in accessing social services: absent or insufficient paramedical resources and of practical support in daily life.
  8. Rarely are ther effective treatments or cures: in some cases, symptoms can be treated to improve quality of life and longevity.
  9. Financial burden: An affected person is often unable to work and in the case of a child, a parent must leave their job to care for them.
  10. Expensive treatments and inequalities in access to treatments and care: drugs not always reimbursed by public drug plans or private insurance.

See here the RQMO’s work since its creation to improve the lives of those affected by rare and orphan diseases in Quebec

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