Genetic polymorphism of human parotid salivary amylase detected by isoelectric focusing electrophoresis and silver staining.

In 332 samples of human parotid saliva collected at random from a Japanese population, the genetic polymorphism of salivary alpha-amylase was detected by isoelectric focusing electrophoresis in a pH range of 5.2-7.2 polyacrylamide gel followed by silver staining. This polymorphism, that was tentatively designated Amy1 S, consisted of extra three isozymes of a normal pattern (Amy1 N) and isoelectric points of these three isozymes were 5.5, 5.8 and 6.1, respectively. The inheritance was controlled by a dominant allele at an autosomal locus. The frequency of the genes determining these phenotypes were studied as follows: Amy1 S = 0.014 +/- 0.004, Amy1 N = 0.986 +/- 0.004.