A rare disease

According to the French Institute for Health Monitoring (INVS), a disease is defined as rare if it does not affect more than one person in 2,000, i.e. less than 30,000 people in France with the same disease. Approximately 4 million people in France suffer from them.

Examples of rare diseases

There are more than 7,000 rare diseases listed to date, 80% of which are genetic diseases. Most of these present in early life and can be incapacitating.

A few examples are familial breast cancer, multiple sclerosis, Marfan's syndrome, infantile apnoea, myopathies, haemophilia, etc.

Treatment of rare diseases

Because of the large number of different diseases, each disease affects very few patients. The total population affected is large and apart from the ethical issue, it merits attention from the public authorities and providers of finance at least from a public health perspective.

However, the incidence of these diseases is such that they affect too small a population to enable treatments to be developed and marketed profitably. Many rare diseases are therefore also considered to be "orphans", that is, only symptomatic treatment is available.