Objective: To analyze the rare alleles of D13S325 locus which fell in the size range of D12S391 locus with the STRtyper-10G kit.
Methods: Genotyping results of cases with suspected rare alleles of D13S325 were verified with Sinofiler(TM) kit and a singleplex amplification system. The rare alleles were separated and sequenced.
Results: Five families were detected with rare alleles of the D13S325 locus, which were misread as allele 20 of D12S391 locus. The alleles were named as 5.1 based on DNA sequences and have a frequency of 0.156 × 10(-2).
Conclusion: As the rare allele 5.1 of D13S325 locus with the STRtyper-10G kit is prone to be mistyped, attention should be paid in the paternity testing, personal identification and DNA database search.