Mutation analysis of 24 short tandem repeats in Chinese Han population

Abstract

Germline mutations of 24 short tandem repeat (STR) loci (TPOX, D3S1358, FGA, D5S818, CSF1PO, D7S820, D8S1179, TH01, vWA, D13S317, Penta E, D16S539, D18S51, Penta D, D21S11, D2S1772, D6S1043, D7S3048, D8S1132, D11S2368, D12S391, D13S325, D18S1364, and GATA198B05) were studied for 6,441 parent-child meioses taken from the paternity testing cases in Chinese Han population. In total, 195 mutations were identified at 22 of the 24 loci. Among them, 189 (96.92%) mutations were one step, five mutations (2.56%) were two step, and one mutation (0.51%) was three step. No mutation was found at the TH01 and TPOX loci. The overall mutation rate estimated was 0.0013 (95% CI 0.0011-0.0015), and the locus-specific mutation rate estimated ranged from 0 to 0.0034. There was a bias in the STR mutations that repeat gains were more common than losses (∼1.7:1). Mutation events in the male germline were more frequent than in the female germline (∼4.3:1). Furthermore, loci with a larger heterozygosity tended to have a higher mutation rate. Mutation in short alleles was biased towards expansion, whereas mutation in long alleles favored contraction. The long alleles have a higher allelic mutational probability than short alleles.

Genetic polymorphism of 22 autosomal STR markers in a Han population of Southern China

“…Hence, we present the mapping positions and genetic locations of the 22 STR loci, as well as common forensic loci on the same chromosome, in Table S3. In addition, the mutation rates of 7 out of the 22 STRs have been reported in references [18] and [19]. Their results indicated that the mutation rates were similar to those of commonly used forensic STR loci.…”

Allele and Haplotype Diversity of 26 X-STR Loci in Four Nationality Populations from China

“…Our results are consistent with those of Fracasso [22], Shin [23] and Szibor et al [24]. Mutation rate of the same order was also described for autosomal STR [25].…”

Risk analysis of duo parentage testing with limited STR loci

“…In this study, 4 motherless cases with 2 STR exclusions were excluded for parentage because all of them had over 4 STR mismatches with the mother's STRs (PI < 0.0001). The average STR mutation rate for the Identifiler system was 1.387 x 10 -3 , with the single-step mutation rate being higher than the two-step rate, and the ratio of mutation events in male versus female germlines was 1.6:1 (Table 3), matching previous reports (Lu et al, 2012).…”

“…In general, investigators would consider the duo cases without any mismatches using a limited number of loci. The mutation rate of STRs is low in parentage cases (Yan et al, 2006;Lu, 2012), but the locus mutations in duo cases are important for deciding parentage (Katsumata et al, 2001).…”