Numerous polymorphic microsatellites in the human prion gene complex (including PRNP, PRND and PRNT).

Microsatellite sites were analysed with DNA screening software by using about 148 kilobases (kb) of the human genomic DNA sequence GenBank accession number (acc. no.) which includes the genes PRNP, PRND and PRNT. Regarding microsatellites (MS) with at least four repeats and base replacements within the repetitive motifs<10%, 127 sites were found. Sixteen of the sites were analysed and nine of them proved to be polymorphic with up to nine alleles per site. Frequencies<0.95 of the predominant allele were observed for all polymorphic sites, and frequencies<0.4 for four sites. Some allelic DNA sequences were not only different in microsatellite repeats but also in flanking regions. Distances between microsatellite sites were in average of 1.2 kb and allow the identification of a number of further informative markers in the prion protein gene complex. The large number of polymorphic sites within a narrow chromosomal interval can be applied to study the origin of alleles as well as the association to the incidence of diseases.