Biostatistical Evaluation of Evidence from Single Locus Hypervariable DNA Probes: Tests of Independence of Loci

Abstract

Standard calculation of phenotype matching frequency or paternity index (PI) for multiple genetic systems requires an assumption of independence of loci. We have previously presented a discussion and preliminary tests of independence of phenotypes and independence of presence of alleles within phenotypes for single locus hypervariable DNA probe systems [1]. For disputed parentage, tests of independence of haplotypes more directly address the issue of multiplication of PI’s. However, this method requires knowledge of genotypes, so family studies are required. As we have noted, such data can be obtained from paternity case material. We present here some preliminary data regarding haplotype independence from four single locus probe systems — pS194/Pst I (D7S107), pL336/Pst I (D1S47), pL427-4/Pst I (D21S112) and YNH24/Hae III (D2S44) for three racial groups.