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WJLA, February 29, 2012

Rare Disease Day: 10 rare diseases and their symptoms

A disease is considered rare if it affects less than 200,000 Americans. According to NIH, there are 6,800 such diseases affecting nearly 30 million people. Feb. 29 is Rare Disease Day, which aims to increase awareness about these conditions. 

Narcolepsy

Narcolepsy is characterized by excessive sleepiness and sleeping at inappropriate times, like while at work. Narcoleptics generally experience the REM stage of sleep within five minutes of falling asleep. Most people don't experience REM sleep until at least an hour after falling asleep.