It was thought that identification of the cystic fibrosis gene—the cystic fibrosis transmembrane conductance regulator—15 years ago would lead to the solution for many of the serious consequences of this most common inherited fatal disorder. Instead, over 1000 mutations of this single gene have been reported with varied disease manifestations for each of these different mutations for cystic fibrosis. Substantial variations in the disease within the same CFTR genotype have been found. The impact of CFTR on other conditions such as infertility, diarrhoeal diseases (cholera), and asthma, has been described. This highlights the need for further investigation to better understand the mechanisms for the varied phenotypic expression of these numerous polymorphisms of CFTR.

In this issue, Callaghan and colleagues¹ report on growth and lung function in Asian patients in the United Kingdom with cystic fibrosis. They found …