Likelihood Calculations in Paternity Testing on the Basis of DNA-Fingerprints

DNA-fingerprints seem to be a powerful tool in paternity testing. But the quantification of the results in terms of likelihood and likelihood ratios is a problem, because in most cases the correct genetic model and its parameters are not known. Two approaches have been suggested to circumvent these problems. The use of band sharing rates to distinguish between pairs of relatives and pairs of unrelated individuals, and the calculation of likelihood ratios on the basis of simplifying assumptions. The first approach reduces the available genetic evidence to “phenotypic” similarities. The second one makes unjustified simplifying assumptions. These two decision strategies have to be examined wit…