This entry on the list is a little different from the rest, but it still has a significant -- though hidden -- effect on the population. "Rare disorder" is a classification given to diseases that afflict 200,000 or fewer people in the United States. Compared to other diseases on the list, that isn't a lot.
But combine the roughly 6,800 rare disorders together, and there are 25 million to 30 million affected people in the U.S. [source: NIH] And given the dynamics of disease research and advocacy, where patient population size can dictate which diseases get attention from drug makers, that's a large section of the population whose lives are disrupted by possibly untreatable diseases. Some of the diseases on the list are well known, such as certain types of muscular dystrophy.
But politics has become a saving grace for some people afflicted with rare disorders. Thanks to grassroots advocacy by a network of families with these diseases, Congress passed the Rare Diseases Act of 2002 and the Rare Diseases Orphan Product Development Act, also in 2002. These pieces of legislation provide funding for research on new ways to treat these diseases. Without government intervention, drug makers would have little financial motivation to produce medicines for such small patient groups [source: NORD].
Finding treatment for these rare disorders is a slow process. But thanks to a Social Security Administration initiative in 2008, patients with one of 25 rare disorders can use a streamlined process to obtain Social Security benefits, easing their financial burden as they wait for a cure [source: NIH].