Genetic polymorphism of proline-rich human salivary proteins.

In randomly collected saliva samples from 120 Caucasians, 79 Blacks, and 40 Chinese, three phenotypes were observed by electrophoresis in alkaline slab polyacrylamide gels. The proteins showing polymorphism were identical with four previously characterized proline-rich proteins. Inheritance is controlled by two autosomal codominant alleles. The gene frequencies were for Caucasians, Pr(l)=0.73, Pr(2)=0.27; for Blacks, Pr(1)=0.80, Pr(2)=0.20; for Chinese, Pr(l)=0.84, Pr(2)=0.16.