We determined the allele frequencies for three hypervariable DNA loci D2S44, D1S7 and D7S21 using the probes YNH24, MS1 and MS31 in the genetically isolated Finnish population. The allelic length ranges were 1.7- < 6.0 kb for YNH24, 1.7- < 18.0 kb for MS1 and 3.2- < 12.0 kb for MS31. High heterozygosity rates (0.94-0.96) were detected for all three probes. In 48 mother-child pairs no mutations were found using the probes YNH24 and MS31, whereas a mutation rate of 0.064 was observed for probe MS1. In addition, an unexpected four-band pattern was detected in 1 out of 170 individuals using the probe MS1, suggesting complex DNA polymorphism based on both a variable number of tandem repeats and restriction site polymorphism. Our findings also show that all three probes are valuable in individual identification in this genetically isolated population.