Despite the rarity of each rare disease, it is always surprising for the public to discover that according to a well-accepted estimation, "about 30 million people have a rare disease in the 25 EU countries", Background Paper on Orphan Diseases for the "WHO Report on Priority Medicines for Europe and the World" - 7 October 2004 which means that 6% to 8% of thetotal EU population are rare disease patients. This figure is equivalent to the combined populations of the Netherlands, Belgium and Luxembourg. Quoting from the Background Paper on Orphan Diseases for the "WHO Report on Priority Medicines for Europe and the World" - 7 October 2004: "Unfortunately, the epidemiological data that are available are inadequate for most rare diseases to give firm details on the number of patients with a specific rare disease. In general people with a rare disease are not registered in databases. Many rare diseases are summed up as "other endocrine and metabolic disorders" and as a consequence, with few exceptions, it is difficult to register people with a rare disease on a national or international basis, and in a reliable, harmonised way". In the case of rare cancers, many registries do not publish sufficient data that break down figures of rare tumours by type, even though this information might be available from pathological examination of tissue removed during surgery. It is worth noting that each and every one of us is, statistically speaking, a carrier of 6 to 8 genetic abnormalities, which are, usually but not always, recessive ones in their transmission. These abnormalities generally have no consequences, but if two individuals carrying the same genetic abnormality have children, these may be affected.

"Rare Diseases : Understanding this Public Health Priority" Eurordis, November 2005 - www.eurordis.org