Cystic fibrosis heterozygote detection: a family study.

Family studies have been done to determine if the phenotypes described for 
the cystic fibrosis (CF) cultured cell reliably detected the CF gene. 
Two culture phenotypes were studied in culture derived from consecutive generations 
in four CF families: (1) cystic fibrosis factor (CFF) in the 
medium of short-term white blood cell cultures assayed by a modified 
oyster ciliary test and (2) the three characteristics of cultured skin 
fibroblasts (metachromasia without alcianophilia at 0.3 M MgCl2, CFF in the 
culture medium and metabolic cooperation with normal fibroblasts). As CF is 
an autosomal recessive disorder, the family offered a test unit for 
determining the specificity of these cell phenotypes for the CF gene. 
On the basis of detecting the CF culture phenotypes in the 
homozygote and obligatory heterozygotes, the parents, and their segregation in consecutive 
generations, detection of the CF gene was not possible in the 
white blood cell cultures, but was possible in the skin fibroblast 
cultures. 