Serum pancreatic isoamylases in the diagnosis of cystic fibrosis heterozygotes: A non-valuable test.

A group of 102 obligate heterozygotes for the cystic fibrosis gene were 
examined for genetic type of pancreatic isoamylases as well as enzyme 
activity of pancreatic iso-amylases, salivary isoamylases and total amylase in serum. 
The analysis was performed using electrophoretic separation for detection of the 
various types of isoamylases, and their relative activity was determined by 
means of densitometry. The activities of salivary isoamylases and total amylase 
in serum showed no significant differences between the cystic fibrosis heterozygotes 
and a control group. The frequency of the variant gene for 
pancreatic isoamylase was also the same as in the controls. The 
mean value for pancreatic isoamylase was slightly higher in the cystic 
fibrosis heterozygotes than in the control group (0.05 greater than P 
greater than 0.02). 