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.