Exclusion of paternity without testing the mother.

On the basis of the existence of incompatible phenotypes between the child and the alleged father, exclusion of paternity can be obtained even when the mother is not available for testing. Incompatible phenotypes in each genetic marker system of common erythrocyte antigens and enzymes, serum proteins, and major histocompatibility antigens are compiled. The efficiencies of each system and groups of systems in the exclusion of paternity are estimated; the cumulative chance is about 88% if all the common genetic marker systems are utilized.