A rare disease, also referred to as an orphandisease, is any disease that affects a small percentage of the population.
罕见病，也被称为孤儿病，指那些仅在极少数人群身上发生的疾病。
2
Orphan drug designation is available for drugs already approved for another disease or condition or for experimental drugs that have not been previously approved.
已经被批准用于其它疾病治疗的药物或者是尚处于试验阶段未被批准的药物都可以通过孤儿药物申报程序进行。
3
This study thoroughly examines the following markets: orphan diseases, Gaucher's Disease and Pulmonary Arterial Hypertension (PAH) markets in Europe.