The US Food and Drug Administration (FDA) recently awarded $14 million in grants to boost the development of drugs or devices for rare diseases (http://1.usa.gov/1bPq5q8).
The Orphan Drug Act was passed in 1983 to promote the development of treatments for roughly 6800 rare diseases and conditions that currently affect nearly 30 million US individuals. In awarding grants for orphan drug research, the FDA considers treatments for conditions that affect fewer than 200 000 persons. For devices, the Humanitarian Use Device program is geared toward devices for conditions that affect fewer than 4000 in the United States per year.
Kuehn BM. FDA Funds Development of Drugs and Devices for Rare Diseases. JAMA. 2013;310(20):2140. doi:10.1001/jama.2013.283509