"About 95 percent of all rare diseases have no approved drug treatments..... But taken as a whole, rare diseases are not unusual: An estimated 30 million people in the country — or about 10 percent of the population — are living with one of the nearly 7,000 rare diseases that have been identified.

Prompted by financial incentives passed by Congress, the drug industry is hotly pursuing treatments for a throng of rare diseases. That has led to breakthroughs in several conditions, including cystic fibrosis and spinal muscular atrophy. Nevertheless, with a small number of subjects to study and relatively few people to sell new drugs to, many rare diseases are overlooked by doctors and scientists, hampered by a lack of resources and public awareness."

Article about a doctor who got a rare disease -- no one could even diagnose it -- so he became a researcher for his own disease.

This is a NY Times article so you'll use up one of your 10 free articles a month (assuming you're not a subscriber)

https://www.nytimes.com/2017/02/04/business/h...h_20170205