Cystic Fibrosis One out of every 2,500 births in the united states will be diagnosed With cystic fibrosis. This fact makes cystic fibrosis one of the most common Genetic diseases in the nation. About 30,000 americans have the disease, but Even though cystic fibrosis is the nations most common genetic disease the Majority of americans know little about it. Cystic fibrosis is relatively Common in calcastion people but rare in african-american. The disease is very Uncommon in mongolians. Five percent of the population in the united states are Carriers of the genetic disease. Cystic fibrosis, someti