[Paternity index. Application to a sample of 48 trios presumptive father-mother-child. Study of the relationship between the probability of paternity and the percentage of exclusion].

Two different indices are of interest in paternity diagnosis. 1. The proportion of men whose paternity is excluded by mother and child phenotypes. 2. The posterior probability of paternity, obtained by a bayesian process from the phenotypes of putative father, mother and child. These two indices are different, and it is proposed that the first one be used for gauging the value of the second. Two examples of the method are given: first, a sample of 48 putative father-mother-child trios, observed in the probability of paternity versus proportion of excluded men plane at different steps on the laboratory examinations, second, the figure obtained for a child for whom two putative fathers were at examination.