The genetic polymorphisms of nine Y-STR loci with short fragment size alleles in southern Chinese Han population and its application in forensic science / 中华医学遗传学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To study the genetic polymorphisms of 9 Y-chromosome specific STR loci that the allele size is less than 180 bp in length in the southern Chinese Han population, and to utilize the studied result to forensic science.</p><p><b>METHODS</b>Nine Y-STR loci were amplified by single multiplex PCR, and the PCR products were sequenced by using ABI Prism 3100 DNA Sequencer. The allele and haplotype frequencies at 9 Y-STR loci were determined in a total of 213 unrelated males from southern Chinese Han population. Eighty-four father/son pairs with demonstrated paternity and thirty-six non-paternity father/son pairs were detected by using our Y-STR multiplex system.</p><p><b>RESULTS</b>Three Y-STR alleles for DYS426, five alleles for DYS393, DYS460, DYS391 and DYS389 I respectively, six alleles for DYS456, seven alleles for both H4 and DYS388, and eight alleles for DYS458 loci were detected in 213 unrelated male individuals. Except for the DYS426 locus with a low GD value of 0.1489, the GD values for other 8 Y-STR loci ranged from 0.5064 to 0.9133. A total of 178 haplotypes were found at 9 Y-STR loci, of which 154 haplotypes were observed only once, and the haplotype diversity was 0.9983. None of Y-STR allele mutation was observed in the 84 father/son pairs with demonstrated paternity. Among the 36 non-paternity father/son pairs, two cases could get the paternity exclusions at 2 Y-STR loci; and the paternity of 33 cases could be ruled out by 3 or more Y-STR loci; only one case was found no exclusion of paternity regardless of detecting 9 Y-STR loci.</p><p><b>CONCLUSION</b>This result indicates that the 9 Y-STR loci with short fragment size alleles are highly polymorphic. The fluorescent multiplex amplification system that we developed is suitable for personal identification and paternity testing.</p>