Frequency of restriction site polymorphisms in the region surrounding VNTR loci.

Variations in allele size in loci containing tandem repeats result from changes in the number of these repeats. However, digestion of the same DNA samples with two restriction enzymes (i.e. PstI and HaeIII), that have recognition sites predominantly in the DNA region flanking the VNTR, has identified the presence of numerous site polymorphisms. Three loci (D2S44, D4S163, D17S79) were examined for the presence of restriction site polymorphisms in both North American Black and Caucasian populations. At all loci there were alleles with site polymorphisms. This type of variations were more common in the North American Black than in the Caucasian populations.