Cystic-fibrosis variants--or variations? [editorial].

Cystic fibrosis is inherited by single autosomal transmission. That, at least, is 
the general view; but from time to time other suggestions are 
offered. Stern et al. describe what they believe may be a 
genetic variant. The affected patients, they suggest, are homozygous for a 
portion of a closely linked multigenic cystic fibrosis locus, or have 
modifier genes ameliorating the pancreatic and sweat lesions. Do these patients 
really have CF? And, if so, are Stern et al. justified 
in suggesting that they differ genetically from the "classic" CF patient? 
This hypothesis may not be correct but, until we understand the 
basic fundamental defect, it may be unwise to divide CF into 
different genetic types on the basis of clinical variations. 