The Diagnosis of Cystic Fibrosis

Cystic fibrosis is an autosomal recessive disease caused by mutations of a gene located on the long arm of chromosome 7.1 The gene product is the 1480-amino-acid cystic fibrosis transmembrane conductance regulator (CFTR), a protein that normally regulates and participates in the transport of electrolytes across epithelial-cell membranes and probably across intracellular membranes as well.2 Recent advances in genetics and molecular biology have led to the introduction of new tests for cystic fibrosis and to a reconsideration of the spectrum of the disease.Although the primary manifestations are presumably related, at least in part, to abnormal transport of electrolytes, the . . .