Assigning probabilities to alleged relationships, given DNA pro®les, requires, among other things, calculation of a
likelihood ratio (LR). Such calculations usually assume independence of genes: this assumption is not appropriate when the
tested individuals share recent ancestry due to population substructure. Adjusted LR formulae, incorporating the coancestry
coef®cient FST, are presented here for various two-person relationships, and the issue of mutations in parentage testing is also
addressed.