<P> In the United States , the Rare Diseases Act of 2002 defines rare disease strictly according to prevalence , specifically `` any disease or condition that affects fewer than 200,000 people in the United States '' , or about 1 in 1,500 people . This definition is essentially the same as that of the Orphan Drug Act of 1983 , a federal law that was written to encourage research into rare diseases and possible cures . </P>
<P> In the United States , the Rare Diseases Act of 2002 defines rare disease strictly according to prevalence , specifically `` any disease or condition that affects fewer than 200,000 people in the United States '' , or about 1 in 1,500 people . This definition is essentially the same as that of the Orphan Drug Act of 1983 , a federal law that was written to encourage research into rare diseases and possible cures . </P>
a disease is considered as rare disease if
a disease is considered as rare disease if
affects fewer than 200,000 people in the United States
affects fewer than 200,000 people in the United States