[Polymorphism and Mutation Rate of 20 Rapidly Mutating Y-Chromosomal Short Tandem Repeats in Chinese Han Population of Sichuan Province].

Objective: To explore the applicability of 20 rapidly mutating Y-chromosomal short tandem repeats (RM Y-STRs) in Chinese Han population of Sichuan province.

Methods: Two RM Y-STR multiple amplification systems (RM1, including DYF404S1, DYF399S1, DYS547, DYS526a/b, DYS626, DYF403S1a/b, and DYS612, and RM2, including DYS1003, DYS1007, DYR88, DYS712, DYS711, DYS724, and DYF1002, with 14 RM Y-STR loci in total) and Y41SE-V1.2 (including 6 RM Y-STR loci of DYS627, DYS576, DYF387S1, DYS518, DYS570, and DYS449, 30 ordinary Y-chromosomal short tandem repeats [Y-STR] loci, and 1 Indel locus) were used for the amplification and typing of 200 unrelated males and 260 father-son pairs. The polymorphisms and mutation rates of 20 RM Y-STRs and 30 ordinary Y-STRs in Chinese Han population of Sichuan province were investigated and compared.

Results: In the 200 unrelated males, the gene diversity (GD) of 20 RM Y-STR loci ranged from 0.7910 to 0.9975, and there were 200 haplotypes. Haplotype diversity (HD) was 1 and the discriminative capacity (DC) was 1. A total of 198 haplotypes were found in Y41se-v1.2 (the 30 Y-STRs), with 4 cases sharing two haplotypes, the haplotype diversity being 0.9999, and the discriminative capacity being 0.99. A total of 68 mutations were found at the 20 RM Y-STRs loci in the 260 father-son pairs, and there was slightly more increase than decrease of allele repeats (1.19∶1), with the mutation rate ranging from <3.85×10 (95% : 0.00-1.41×10 ) to 2.69×10 (95% : 1.09×10 -5.47×10 ), and the average mutation rate being 1.19×10 (95% : 9.20×10 -1.51×10 ). The 20 RM Y-STRs and the Y41SE-V1.2 (the 30 Y-STRs) could be used to distinguish 22.3% and 13.8% father-son pairs, respectively.

Conclusion: The 20 RM Y-STRs have high gene and haplotype diversity and paternal lineage differentiation rate in Chinese Han population of Sichuan province, showing great potential for application in Chinese Han population of Sichuan province.