Cystic fibrosis: cell culture classes in a Danish population.

The cystic fibrosis (CF) culture phenotype of dermal fibroblasts (metachromasia, metabolic cooperation) 
of a group of 131 Danish CF patients and their families 
were studied to determine the distribution of the two CF culture 
classes and their prognostic significance. Of these, 62.6% (82) were Class 
I, 31.3% (41) Class II and 61.1% (8) were proposed to 
be genetic compounds. The occurrence of Class II was twice that 
found in a group of patients from New York (13%) and 
Minnesota (18%). The prognosis for Class II CF patients was considered 
to be poorer as: (1) The initial diagnosis was made earlier 
in Class II than in Class I or the compounds (63% 
of Class II were diagnosed in the first year of life, 
as compared to 35% in Class I and 13% of the 
compounds). (2) Only 5% of the Class II patients survived over 
the age of 15 years, both being deceased at the end 
of the study in 1976, whereas 24% of Class I and 
63% of the compounds were over 15 years at the end 
of the study. This research added further evidence for genetic heterogeneity 
within the clinical syndrome, cystic fibrosis. 