Cystic fibrosis.

Cystic fibrosis is the most frequent lethal genetic syndrome among white children 
and is the cause of much of the chronic progressive pulmonary 
disease encountered in children. Because of the increasing adolescent and adult 
population of patients with cystic fibrosis and their psychosocial, employment, and 
treatment needs, this review, whenever possible, will emphasize aspects pertinent to 
older patients. No known biochemical or structural defect will account for 
all the pathophysiologic phenomena of cystic fibrosis. Thus, the definition of 
the disease rests on the clinical findings; cystic fibrosis is a 
syndrome, and not yet a disease. Incidence figures for cystic fibrosis 
are necessarily minimal. The best diagnostic efforts currently available fail to 
detect all those who die at a young age or who 
have mild symptoms. Several pieces of evidence indicate that cystic fibrosis 
is transmitted as an autosomal recessive trait. An autosomal recessive inheritance 
for cystic fibrosis suggests a discrete biochemical or structural defect. To 
date no single lesion has been proved to provide a unifying 
hypothesis for the pathophysiology of cystic fibrosis. Exocrine gland dysfunction, mucociliary 
transport, immunology, ciliary factors and transport mechanisms are discussed. The manifestations 
of cystic fibrosis involve many organ systems and the pattern of 
presentation is variable. Respiratory, gastrointestinal, genitourinary, and sweat gland manifestations are 
discussed. There are at least 3 possible approaches to screening for 
cystic fibrosis: sweat testing, evaluation of pancreatic function, or detection of 
some product of the defective gene. Prenatal diagnosis and heterozygote testing, 
diagnosis in adults, and diagnostic problems are also examined. Treatment includes 
prevention, pulmonary therapy, and gastrointestinal therapy. Pulmonary and other complications and 
their treatment are discussed, as well as psychosocial aspects, and evaluation 
and prognosis of cystic fibrosis. 