Narod SA. Tamoxifen ChemopreventionâEnd of the Road?. JAMA Oncol. 2015;1(8):1033â1034. doi:10.1001/jamaoncol.2015.2247. Download citation file:
About Rare Diseases. A rare disease is defined by the European Union as one that affects less than 5 in 10,000 of the general population. There are between 6,000 and 8,000 known rare diseases. Around five new rare diseases are described in medical literature each week.
Orphan drugs - Statistics & Facts. Statistics and facts about orphan drugs. A rare disease is characterized by the number of people that it affects in comparison to the general population. Based on European standards, a disease is considered rare if it impacts one person per 2,000.