Cystic fibrosis is a genetic disorder that affects the lungs and causes nutritional deficiencies. It is caused by a defective recessive gene. This means you have to inherit the defective gene from each parent to have the condition. Millions of Americans have one defective gene and are carriers of cystic fibrosis. Carriers can pass the defective gene onto their offspring, but carriers themselves do not exhibit symptoms of cystic fibrosis. Approximately one in 29 Americans are carriers of cystic fibrosis [source: PubMed Health].
People of Northern and Central European descent are more likely to carry the defective gene for cystic fibrosis. The condition occurs in approximately one in 3,000 live births in America [source: Mayo Clinic]. Although this statistic may give the impression that cystic fibrosis is rare, it is the most common genetic condition in North America. In Great Britain, the prevalence of cystic fibrosis is even higher, occurring in one in 2,500 live births. Approximately 7,000 people currently have cystic fibrosis in the United Kingdom [source: Patient.co.uk].
Cystic fibrosis is normally diagnosed before the age of two. Some people, however, remain undiagnosed until much later in life. Historically, people would die from cystic fibrosis symptoms in their teens. Modern technology and research, however, has greatly improved treatment for cystic fibrosis. Therefore, today, it is common for people to live well-into their fifties or later with the condition [source: Mayo Clinic]. Due to the longer lifespan, the prevalence of cystic fibrosis in the general population is increasing.
Over 1,000 possible genetic mutations of a particular gene can lead to cystic fibrosis. For this reason, people with the condition experience varying degrees of lung and gastrointestinal-related symptoms [source: PubMed Health]. Cystic fibrosis is diagnosed with a standard blood test, which many hospitals routinely perform when an infant is born.