[Orphanet and its consortium: where to find expert-validated information on rare diseases].

There are approximately 6000 rare diseases, and 80% of them are genetic. In Europe, a disease is considered rare when it affects no more than one person in 2000. In France, two to three million people are affected, while nearly 30 million others are affected across Europe (5-8% of the whole European population). The majority of rare diseases are poorly understood by health professionals. Due to the lack of sufficient scientific and medical knowledge, many patients are misdiagnosed, which results in delays in care that can be harmful. Because many rare diseases are often associated with neurological manifestations, the neurologist in his daily practice may often encounter these complex diseases that require special care as well as a multidisciplinary approach. Orphanet is the reference portal for rare diseases. Freely accessible on the Internet, it is a non-profit service officially supported by the French Ministry of Health and the European Commission. Its mission is to keep healthcare professionals and patients informed and, by so doing, it contributes to improvements in the diagnosis and treatment of rare diseases. It is currently the only project that establishes a link between diseases and any published information concerning them, and the appropriate services for patients as well as healthcare professionals. Orphanet is currently the most comprehensive site in terms of referenced and documented data, and it has in just a few years become the global reference portal for rare diseases and orphan drugs for all audiences. Orphanet generates a million page views per month. The site is available in six languages (English, French, Spanish, Italian, German and Portuguese) and offers a range of services, including: an inventory, classification and peer-reviewed encyclopedia of rare diseases along with the associated genes (more than 2000 diseases with neurological manifestations are described); a diagnostic support tool; clinical and emergency guidelines; a directory of specialised services in 37 partner countries; an encyclopedia aimed at the general public; an inventory of orphan drugs; downloadable thematic studies and reports on such subjects as the prevalence of rare diseases, orphan drugs, aids and services for patients; and numerous links to other sources of information. Five to ten new rare diseases are described every month, which represents a major challenge for health professionals in terms of keeping their knowledge up to date. The Orphanet website content is expert-validated and updated continuously to respond in real time.