Cystic fibrosis, a generalized disease of exocrine glands, manifests itself clinically by loss or diminution of pancreatic exocrine secretions, by increased susceptibility to upper respiratory infections, and pneumonia resulting in the pathologic changes of bronchiectasis, atelectasis, and emphysema, and by elevations of sodium and chloride concentrations in sweat gland secretions. In addition to the major manifestations, there is evidence pointing to an increase in salivary sodium and chloride concentrations, and abnormal duodenal mucosal gland secretions.
The familial nature of cystic fibrosis was first described by Andersen and Hodges1 in 1946. A few years later, Lowe, May, and Reed,2 using their own family data, and Carter,3 analyzing the previously reported cases as well as his own, concluded that the inheritance pattern could best be explained on the basis of an autosomal recessive gene. More recently, Steinberg and his co-workers4,5 have attempted to establish a possible linkage between