The spectrum of cystic fibrosis in children and adults.

Cystic fibrosis, an autosomal recessive disorder, remains the most common lethal genetic 
disease of Caucasian people. The diagnosis of CF is usually made 
based upon the clinical presentation of chronic respiratory and/or gastrointestinal symptoms, 
a positive sweat electrolyte test and, often, a family history of 
the disorder. The manifestations of chronic cough, recurrent pneumonias, bronchiectasis with 
clubbing, pneumothorax, hemoptysis, and malabsorption secondary to pancreatic insufficiency are so 
well associated with cystic fibrosis that the diagnosis is usually not 
delayed. However, it is often not appreciated by physicians that CF 
may be associated with a broad spectrum of less common manifestations 
as well as extreme variability in severity of illness. Lack of 
familiarity with these manifestations may delay diagnosis until adolescence or adulthood. 
First, there seems to be mild clinical expression of the disorder 
in some patients (genetic variability). Second, the subtle manifestations of CF 
are not widely appreciated by physicians in practice. 