Abstract: Objective To evaluate the utility of 6 miniSTR loci (D1S1677, D2S441, D4S2364, D10S1248, D14S1434, and D22S1045) in highly degraded DNA samples, and to investigate the genetic polymorphism in Guangdong Han population. Methods The loci of 6 mini-STR in Han population of Guangdong were genotyped by primers labeled with four-color fluorescent (FAM, HEX, TAMRA and ROX) and two multiplex amplification reaction systems. Results Each locus was successfully genotyped with the product fragment less than 120 bp. Among the 216 individuals investigated, 7, 7, 5, 8, 8, and 7 alleles, and 14, 11, 11, 19, 12, and 14 genotypes were detected at D1S1677, D2S441, D4S2364, D10S1248, D14S1434, and D22S1045, respectively. No deviation from Hardy-Weinberg equilibrium was observed in these loci. The discrimination power were 0.863, 0.895, 0.792, 0.894, 0.814, 0.904 and the excluding probability of paternity were 0.392, 0.360, 0.353, 0.568, 0.378, 0.513, respectively. The utility of the 6 miniSTR loci assays was confirmed by a higher successful rate for typing 10 highly degraded DNA samples, which were only partially being typed using IdentifilerTM kit. Conclusion The 6 miniSTR loci show genetic polymorphisms in the Han population of Guangdong. Assays for forensic typing the 6 miniSTR loci appear useful in highly degraded DNA samples.

Key words: miniSTR, multiplex PCR, genetic polymorphism, degraded DNA