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.
adjective (rarer, rarest). 1 (Of an event, situation, or condition) not occurring very often: a rare genetic disorder [with infinitive]: itâs rare to see a house so little altered. More example sentences. Synonyms. 1  The best that most of us can do is to live with it, enjoy it and be thankful it is such a rare event.