Paternity testing: analysis of six blood groups and HLA markers, with particular reference to comparison of races.

Blood groups (ABO, Rh, MNSs, Kell, Duffy, and Kidd) and HLA markers were tested in cases involving 563 children of disputed parentage. In 149 (26.5%) cases, the accused men were excluded as the biologic fathers of the children in question. One hundred forty of the 149 exclusions were direct exclusions. Five exclusions were based on red blood cell data alone, i.e., HLA was non-exclusionary. Of the remaining 414 cases in which the alleged father could not be excluded as the biologic father, in 361 (87.2%) instances, the plausibility of paternity ws 95% or greater, and in 385 (93.0%) instances the comparison of men value was 20 or greater. Caucasians, blacks, and men of other races were involved in 367 (65.1%), 185 (33%), and 11 (1.9%) cases, respectively. No significant difference among races was observed in the rate of exclusion of accused men. However, of the non-excluded men, in a significantly greater proportion of black men than white men, the plausibility of paternity was below 95%. The difference was probably due to lower polymorphism of the markers tested in blacks than in whites. It is suggested that tests for additional polymorphic genes be directed towards the 12-15% of the nonexclusionary cases with plausibility of paternity values below 95%.