Genetic variation in the Italian population at five tandem repeat loci amplified in vitro: use in paternity testing.

A multilocus genotype survey of 190 to 352 chromosomes was performed in Italians. Genomic DNA of five tandem repeat loci was amplified in vitro with the polymerase chain reaction. Variable number of tandem repeat (VNTR) or short tandem repeat loci investigated were: D1S80; AP0B, located in the 3' flanking region of the apolipoprotein B gene; D17S5; F8VWF, located in intron 40 of the von Willebrand factor gene; and D6S89. The repeat motif was from 2 to 70 bp. The polymerase chain reaction product size was from 100 to 1070 bp. Relative allele frequencies exhibited bimodal or complex distributions. The number of alleles detected in the sample varied from 10 for F8VWF to 20 for D1S80. The observed heterozygote frequencies of the loci ranged from 0.75 for D17S5 and F8VWF to 0.83 for D1S80, and were in accord with expected frequencies. No mutations were detected in a total of 566 meioses for the five loci studied. The most frequent genotype for all five loci combined has a frequency of 4.1 x 10(-6). In 90 parental determination cases, D1S80, AP0B, D17S5 and F8VWF gave conclusive information in 39/45 exclusions and in 21/45 attributions.