Frequency distribution of the alleles of several variable number of tandem repeat DNA polymorphisms in the Italian population.

Variable number of tandem repeat (VNTR) DNA polymorphisms were studied in a random sample of 100 Italians. The following systems were used: YNH24/MspI, CMM101/MspI, MLJ14/RsaI, EFD64.2/RsaI, EFD64.2/HinfI, JCZ3.1/HinfI and AW101/EcoRI. For each system, the allele size, number and frequency were determined. The number of alleles, for the different VNTRs, varied from 21 to 44, and the heterozygosity from 70 to 90%. All the VNTRs showed a modal distribution of fragment size and overrepresentation of the lower-molecular-weight DNA fragments. All of them exhibited greater variability than that reported for the North American population. These data will be useful for individual identification purposes and for calculating the probability of random inheritance of a particular allele in the Italian population. The results are discussed in relation with the possible mechanism of generation of new-length alleles.