The quest for the basic defect in cystic fibrosis.

The search for the basic defect in cystic fibrosis has so far 
been singularly disappointing. There is no doubt that it is a 
disease recessively inherited, ie that the parents carry the cystic fibrosis 
gene without showing any signs of ill health (heterozygous) but when 
transmitted from both of them to an offspring this child manifests 
the disease, having acquired the abnormal gene in double dose (homozygote). 
Cystic fibrosis is the most common of the genetically determined diseases. 
Two types of cultured cells, fibroblasts and white cells from affected 
individuals and heterozygous carriers for cystic fibrosis, showed characteristic changes of 
metachromasia that seemed to allow for a classification of patients and 
carriers to be distributed into separate classes. Serum from patients with 
cystic fibrosis of the pancreas disorganises the movement of cilia of 
the isolated rabbit tracheal mucosa. One of the early and also 
most constant observations is the 'viscosity' of secretions of the mucosal 
glands in the respiratory tract, in the alimentary apparatus, in the 
biliary system and in the pancreas. A striking increase in the 
levels of sodium and chloride, and to a lesser extent of 
potassium, is present in the sweat of practically all sufferers of 
cystic fibrosis. However frustrating and tantalising the outcome of research into 
the basic defect has been so far, the ultimate answer is 
likely to be astonishing in it simplicity. 