What is the difference between a rare disease and an orphan disease? What is the criterion for labelling a disease as a “rare disease”?

What is the difference between a rare disease and an orphan disease?  What is the criterion for labelling a disease as a “rare disease”?

What is the difference between a rare disease and an orphan disease?  What is the criterion for labelling a disease as a

Alzheimer’s, gluten intolerance, tuberculosis, psoriasis, sarcoidosis, celiac disease, AIDS, trisomy 21, osteosarcoma. Are these rare and orphan diseases?

What is the difference between a “rare disease” and an “orphan disease”, or can a disease be both at the same time?


The European definition of a rare disease, according to the European Union Regulation on Orphan Medicinal Products (1999), is a disease that affects no more than

in the European population; in the USA the ratio of 1 in 1500 individuals is used to qualify rare diseases.

Of course, some diseases are much rarer, sometimes one in millions of people.

A disease may be rare in one region and common in another, but usually when we talk a rare disease we are talking a rare disease globally.

Rare or not rare?


In France in 2020, it is estimated that 1.2 million people will be ill, which represents 1 person in 55. We find approximately the same rate in Quebec. Therefore, Alzheimer’s is not a rare disease at all, it is a common disease;

Celiac disease

This disease is in constant progression and is now evaluated at 1/100, it is not a rare disease;

Multiple Sclerosis

In France, 110,000 people, 3 out of 4 of whom are women; MS is not a rare disease either because it affects about 1 in 610 people; on the other hand, the “progressive from the outset” form can be considered rare because it affects 15% of MS patients, i.e. a prevalence of 1 in 4,066 patients;


Sarcoidosis: Sarcoidosis is considered rare, ranging from 1 to 5 cases per 10,000, depending on the studies;



is about 10 rarer;

Systemic lupus erythematosus.
: 1/2500, so rare;

Friedreich’s Ataxia

One in 50,000! rare;


(previous photo): 1 in 4 million!


More than

7,000 rare diseases

have been catalogued around the world.

Many rare diseases are chronic, progressive and fatal. Almost 75% of these diseases affect children.

About 80% of rare diseases are genetic in origin. Other causes include immune deficiencies, infections, intoxications, teratogens (poisonings or infections during pregnancy), etc. In many cases, the etiology of the disease is unknown.


In fact, it should be referred to as a “rare disease” and “orphan drug” rather than an orphan disease.

A ”

orphan medicine

“is a drug or other medicinal product used for the treatment of a rare disease.

Orphan of what? Research orphan. Orphan of clinical trials. Orphan of production.

A drug is called an “orphan” drug because, to its limited market, it is neglected by researchers and is unlikely to be adopted by a pharmaceutical company.

Since the market for drugs targeting rare diseases is a very small market for a small group of patients, the manufacturer of the drug would probably not be able to recover the development and marketing costs incurred, alone a profit from manufacturing the product.

In this sense, yes, one can speak of an “orphan disease” because these patients are themselves orphaned from adequate drugs due to the lack of availability of orphan drugs, or the cost of such drugs.

Often treatments for rare diseases are based on drugs “borrowed” from other diseases, as I mentioned in my answer on pain


Whatever the symptoms, living with a rare disease can have a very negative effect on health. While this can be said of any chronic disease, the impact is magnified in the case of rare diseases. Anxiety, stress, bad moods, emotional exhaustion and suicidal thoughts have all been identified among people living with a rare disease.

The situation of these patients is complex and several factors influencing their mental health are involved:

Genetics: Since most rare diseases are genetic, there is a fear of passing the disease on to future children.

Chronicity: they are very often chronic, and may involve a high level of physical and psychological suffering, which is more or less relieved by treatments of varying effectiveness, but what is common to almost all of them is that the patient will never find a cure for his or disease.

Diagnosis: normally, when a patient is diagnosed, or she gains a understanding of the disease, an idea of the clinical course and expects treatment. Often the diagnosis can predict that you will get , and it provides information about how long it will take to get . This is usually not the case for rare disease patients because very little is known about each of these diseases. Sometimes the disease remains undiagnosed; the patient may even be misdiagnosed as suffering from a psychosomatic disorder.

The support network: a phenomenon of weariness in the patient’s entourage can also set in and contribute greatly to the patient’s feeling of being a burden and already feeling guilty about his or her condition. It is particularly difficult for both caregivers and patients to remain motivated in the face of an incurable disease, especially if it is a degenerative disease, in the face of a battle that cannot be won. In such a situation, the patient is likely to seek further isolation in order not to darken the life of the healthy.

The mental impact of the unknown often disrupts the life of a patient with a rare disease, leading to social isolation and further deterioration of mental well-being.

Psychiatric Assistance for Rare Diseases

There is little guidance available to psychiatrists on how to work with patients with rare diseases, yet these are patients who are in great need of psychological support. Fortunately, psychiatrists can their practice in a number of ways to work effectively with this population throughout the course of the disease trajectory.


In Canada, less than 1% of the Canadian population accounts for 42% of sales of patented drugs.

Between 2006 and 2017, the number of drugs in Canada with an annual cost per beneficiary of more than $10,000 increased by more than 200% and now accounts for 42% of patented drug sales.

Are catastrophic drugs becoming the norm for new drug launches?

Orphan drugs are increasingly dominating the market and account for almost half of new launches.

In 2016 and 2017, more than one-quarter of the new drugs were indicated for cancer treatment and many were expensive, with an average cost of approximately $13,700 per 28-day treatment cycle.

Most of the non-oncology drugs introduced in 2016 and 2017 were expensive: 31 out of 37 had annual treatment costs in excess of $10,000.
An increasing number of

Expensive Medicines for Rare Diseases” (EMDR) are launched every year.

79 ODBs were approved in Canada at the end of 2018, defined as having received an Orphan Drug Designation and estimated annual treatment costs of more than $100,000 per year (non-oncology drugs) or $7,500 per 28-day cycle (oncology drugs).


This is the fastest growing class of drugs in Canada, particularly for drugs used to treat rare cancers.

Can we decide to deny an MOMR to patients on the basis of the cost of that drug if it is available? What right would we have to do so?


Rare disease patients have the same rights to as other patients, and they too to benefit from advances in science and therapeutics like others. Therefore, in order to stimulate research and development in this sector, public authorities have put in place incentives for the health and biotechnology industries.

This began as early as 1983 in the United States with the adoption of the Orphan Drug Act, followed by Japan and Australia in 1993 and 1997; Europe followed in 1999 with the introduction of a unified orphan drug policy in the Member States.

In order to qualify, the product first obtains “orphan designation” in order to benefit from certain advantages for research and development. Once it has obtained a marketing authorisation, it is called an “orphan drug”. In Canada, there is no separate database for Orphan Drugs.

France has had a National Plan for Rare Diseases since 2004.

. This plan sets as a priority to ensure equity in access to diagnosis, treatment and care for people suffering from a rare disease, the implementation of ten strategic lines of action. In Quebec, the Minister of Health, Danielle McCann, has committed to table a National Plan by 2020.

In Quebec, the Institut national d’excellence en santé et en services sociaux (INESSS) evaluates drugs for reimbursement by the Régime général d’assurance médicament (public plan).



February 29th

is the International Day for Rare Diseases. This day was chosen because it is the rarest day on the calendar; of course, activities that usually take place on February 29th are moved to February 28th in non-leap years. In 2020 it will be Saturday, February 29, 2020