Rapidly Mutating Research Articles

Male Pedigree Toolbox: A Versatile Software for Y-STR Data Analyses.

Y-chromosomal short tandem repeats (Y-STRs) are widely used in forensic, genealogical, and population genetics. With the recent increase in the number of rapidly mutating (RM) Y-STRs, an unprecedented level of male differentiation can be achieved, widening and improving the applications of Y-STRs in various fields, including forensics. The growing complexity of Y-STR data increases the need for automated data analyses, but dedicated software tools are scarce. To address this, we present the Male Pedigree Toolbox (MPT), a software tool for the automated analysis of Y-STR data in the context of patrilineal genealogical relationships. The MPT can estimate mutation rates and male relative differentiation rates from input Y-STR pedigree data. It can aid in determining ancestral haplotypes within a pedigree and visualize the genetic variation within pedigrees in all branches of family trees. Additionally, it can provide probabilistic classifications using machine learning, helping to establish or prove the structure of the pedigree and the level of relatedness between males, even for closely related individuals with highly similar haplotypes. The tool is flexible and easy to use and can be adjusted to any set of Y-STR markers by modifying the intuitive input file formats. We introduce the MPT software tool v1.0 and make it publicly available with the goal of encouraging and supporting forensic, genealogical, and other geneticists in utilizing the full potential of Y-STRs for both research purposes and practical applications, including criminal casework.

Internal validation of an improved system for forensic application: a 41-plex Y-STR panel.

A novel multiplex comprising 41 Y-STR and 3 Y-InDel was developed for forensic application.The multiplex included rapidly mutating Y-STRs and low-medium mutating Y-STRs, which is compatible with many commonly used Y-STR kits.The multiplex is a powerful tool for distinguishing related males, familial searching, and constructing DNA databases.

Tracking B Cell Memory to SARS-CoV-2 Using Rare Cell Analysis System.

Rapid mutations within SARS-CoV-2 are driving immune escape, highlighting the need for in-depth and routine analysis of memory B cells (MBCs) to complement the important but limited information from neutralizing antibody (nAb) studies. In this study, we collected plasma samples and peripheral blood mononuclear cells (PBMCs) from 35 subjects and studied the nAb titers and the number of antigen-specific memory B cells at designated time points before and after vaccination. We developed an assay to use the MiSelect R II System with a single-use microfluidic chip to directly detect the number of spike-receptor-binding domain (RBD)-specific MBCs in PBMCs. Our results show that the number of spike-RBD-specific MBCs detected by the MiSelect R II System is highly correlated with the level of nAbs secreted by stimulated PBMCs, even 6 months after vaccination when nAbs were generally not present in plasma. We also found antigen-specific cells recognizing Omicron spike-RBD were present in PBMCs from booster vaccination of subjects, but with a high variability in the number of B cells. The MiSelect R II System provided a direct, automated, and quantitative method to isolate and analyze subsets of rare cells for tracking cellular immunity in the context of a rapidly mutating virus.

Mutation analysis for newly suggested 30 Y-STR loci with high mutation rates in Chinese father-son pairs

Rapidly mutating Y-STRs (RM Y-STRs) harbor great potential to distinguish male relatives and achieve male identification. However, forensic applications were greatly limited by the small number of the initially identified 14 RM Y-STRs. Recently, with the emergence of 12 novel RM Y-STRs, an integrated panel named RMplex was introduced, which contains all 26 RM Y-STRs and four fast mutating Y-STRs (FM Y-STRs). To obtain the first data on the mutation rates and father-son differentiation rates of the 30 newly proposed Y-STRs in Chinese populations, we performed an empirical mutation study on 307 DNA-confirmed Chinese paternal pairs. Previously reported mutation rates for 14 RM Y-STRs in Chinese and European populations were pooled and merged with our data. The highest meiosis number for the two groups reached 4771 and 2687, respectively. Five loci showed significant differences between the populations (DYS570, DYS399S1, DYS547, DYS612, and DYF403S1b). For the new panel covering 30 Y-STR loci, our results show extensive differences in the mutation rates between the two populations, as well. 10 RM Y-STR loci showed relatively low mutation rates (10–3–10–2 per meiosis) and 2 FM Y-STR loci had rapid mutation rates (> 10–2 per meiosis) in the Chinese population. Several-fold differences in mutation rates were found in nine Y-STR loci between the Chinese and reference populations, with two loci having significantly higher mutation rates and one locus with a significantly lower mutation rate in the Chinese population (P < 0.05). Eighteen RM Y-STRs (> 10–2 per meiosis), 8 FM Y-STR loci (5×10–3-10–2 per meiosis), 3 moderately mutating Y-STRs (MM Y-STRs, 10–3-5×10–3 per meiosis), and one locus with no observed mutation events were identified in the Chinese population. 40.06% of the Chinese paternity pairs were discriminated with RMplex while only 20.84% with the initial 14 RM Y-STRs, indicating that RMplex is beneficial for distinguishing paternally related males. Future studies on populations of different genetic backgrounds are necessary to obtain comprehensive estimates of mutation rates at these new loci.

Developmental Validation of a Rapidly Mutating Y-STR Panel Labeled by Six Fluoresceins for Forensic Research

The male-specific region of the human Y chromosome is a useful genetic marker for genealogical searching, male inheritance testing, and male DNA mixture deconvolution in forensic studies. However, the Y chromosomal short tandem repeats (Y-STRs) are difficult to distinguish among related males due to their low/medium mutation rate. In contrast, rapidly mutating (RM) Y-STRs exhibit unusually high mutation rates and possess great potential for differentiating male lineages. In this study, we developed a novel Y-STRs multiplex amplification assay of 32 RM Y-STRs by fragment analysis using six dye-labeled technologies (FAM, HEX, TAMRA, ROX, VIG, and SIZ). The development and the validation of the kit were carried out in accordance with the Scientific Working Group guidelines on DNA Analysis Methods. Identical allelic profiles of the 32 RM Y-STRs using a DNA 9948 sample as the positive control could be observed at different concentrations of PCR reagents. Further, the RM Y-STRs did not show cross-reactions with other common animal species, and the developed assay could tolerate interferences from common PCR inhibitors and mixed DNA samples. More importantly, the kit showed relatively high sensitivity and could detect trace DNA samples. Genetic distributions of 32 RM Y-STRs in the Guizhou Han population revealed that these RM Y-STRs showed relatively high genetic diversities. In conclusion, the RM Y-STR assay developed here showed good species specificity, high sensitivity, tolerance to inhibitors, and sample compatibility, which can be viewed as a highly efficient tool with high discrimination capacity for forensic male differentiation.

Improving the differentiation of closely related males by RMplex analysis of 30 Y-STRs with high mutation rates

The discovery of rapidly mutating (RM) Y-STRs started to move the field of forensic Y-STR analysis from male lineage identification towards male individual identification. Previously, the forensic value of RM Y-STRs for differentiating male relatives was limited due to the modest number of 13 identified RM Y-STRs. Recently, new RM Y-STRs were discovered, with strong expectations for significantly improving male relative differentiation; however, empirical evidence is missing yet. More recently, the genotyping method RMplex for efficiently analyzing 30 Y-STRs with high mutation rates, including all 26 currently known RM Y-STRs, was introduced. Here, we applied RMplex as well as the current state-of-the-art commercial Y-STR kit: Yfiler™ Plus PCR Amplification kit, to several hundreds of DNA-confirmed father-son pairs. Newly established estimates confirmed the high mutation rates of novel and previous RM Y-STRs. By combining current with previous data, we provide updated consensus estimates of mutation rates for all 49 Y-STRs targeted with both methods. Based on RMplex, 42% of 499 father-son pairs were differentiated, while 14% of 530 pairs based on Yfiler™ Plus, and 48% of 499 pairs based on both methods combined. Regarding brothers, RMplex also clearly outperformed Yfiler™ Plus, with differentiation rates of 62% and 33%, respectively. By combining both methods 72.9% of the brothers showed at least one mutation. For unrelated males, both methods achieved a discrimination capacity of 99.8% and a haplotype diversity of 0.999991, since all males had different haplotypes, except for two, perhaps indicating a hidden paternal relationship. Overall, this study underlines the value of RM Y-STRs in general and RMplex in particular for differentiating male relatives highly relevant in forensic genetics. It provides the first empirical evidence on the high value of RMplex for differentiating close male relatives, which for father-son pairs was almost 60% higher than with the initial set of 13 RM Y-STRs and three times higher than with Yfiler™ Plus. Based on our results from closely related males, we expect RMplex to also improve the differentiation of more distantly related males significantly, which needs empirical demonstration in future studies. We encourage the forensic community to apply RMplex in all forensic cases where a match with a commercial Y-STR kit was obtained between the male suspect and the evidence material, or to solely use RMplex in such cases, aiming to find out if the male suspect or any of his male paternal relatives left the evidence material at the crime scene.

Sequence Variations of 31 Υ-Chromosomal Short Tandem Repeats Analyzed by Massively Parallel Sequencing in Three U.S. Population Groups and Korean Population.

BackgroundRapidly mutating (RM) Y-chromosomal short tandem repeats (Y-STRs) have been demonstrated to increase the possibility of distinguishing between male relatives due to a higher mutation rate than conventional Y-STRs. Massively parallel sequencing (MPS) can be useful for forensic DNA typing as it allows the detection of sequence variants of many forensic markers. Here, we present sequence variations of 31 Y-STRs including nine RM Y-STRs (DYF387S1, DYF399S1, DYF404S1, DYS449, DYS518, DYS570, DYS576, DYS612, and DYS627), their frequencies, distribution, and the gain in the number of alleles using MPS.MethodsWe constructed a multiplex MPS assay capable of simultaneously amplifying 32 Y-chromosomal markers, producing amplicons ranging from 85–274 bp. Barcoded libraries from 220 unrelated males from four populations—African Americans, Caucasians, Hispanics, and Koreans—were generated via two-step polymerase chain reaction and sequenced on a MiSeq system. Genotype concordance between the capillary electrophoresis (CE) and MPS method and sequence variation of Y-STRs were investigated.ResultsIn total, 195 alleles were increased by MPS compared to CE-based alleles (261 to 456). The DYS518 marker showed the largest increase due to repeat region variation (a 3.69-fold increase). The highest increase in the number of alleles due to single nucleotide polymorphisms in the flanking region was found in DYF399S1. RM Y-STRs had more diverse sequences than conventional Y-STRs. Furthermore, null alleles were observed in DYS576 due to primer-binding site mutation, and allele drop-outs in DYS449 resulted from low marker coverage of less than the threshold.ConclusionThe results suggest that the expanded and discriminative MPS assay could provide more genetic information for Y-STRs, especially for RM Y-STRs, and could advance male individualization. Compiling sequence-based Y-STR data for worldwide populations would facilitate the application of MPS in the field of forensic genetics and could be applicable in solving male-related forensic cases.

Generation and Effect Testing of a SARS-CoV-2 RBD-Targeted Polyclonal Therapeutic Antibody Based on a 2-D Airway Organoid Screening System.

Coronavirus disease 2019 (COVID-19) is an acute respiratory infectious disease caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The US FDA has approved several therapeutics and vaccines worldwide through the emergency use authorization in response to the rapid spread of COVID-19. Nevertheless, the efficacies of these treatments are being challenged by viral escape mutations. There is an urgent need to develop effective treatments protecting against SARS-CoV-2 infection and to establish a stable effect-screening model to test potential drugs. Polyclonal antibodies (pAbs) have an intrinsic advantage in such developments because they can target rapidly mutating viral strains as a result of the complexity of their binding epitopes. In this study, we generated anti–receptor-binding domain (anti-RBD) pAbs from rabbit serum and tested their safety and efficacy in response to SARS-CoV-2 infection both in vivo and ex vivo. Primary human bronchial epithelial two-dimensional (2-D) organoids were cultured and differentiated to a mature morphology and subsequently employed for SARS-CoV-2 infection and drug screening. The pAbs protected the airway organoids from viral infection and tissue damage. Potential side effects were tested in mouse models for both inhalation and vein injection. The pAbs displayed effective viral neutralization effects without significant side effects. Thus, the use of animal immune serum–derived pAbs might be a potential therapy for protection against SARS-CoV-2 infection, with the strategy developed to produce these pAbs providing new insight into the treatment of respiratory tract infections, especially for infections with viruses undergoing rapid mutation.

Forensic features and genetic legacy of the Baloch population of Pakistan and the Hazara population across Durand line revealed by Y-chromosomal STRs

The Hazara population across Durand line has experienced extensive interaction with Central Asian and East Asian populations. Hazara individuals have typical Mongolian facial appearances and they called themselves descendants of Genghis Khan's army. The people who speak the Balochi language are called Baloch. Previously, a worldwide analysis of Y-chromosomal haplotype diversity for rapidly mutating (RM) Y-STRs and with PowerPlex Y23 System (Promega Corporation Madison, USA) kit was created with collaborative efforts, but Baloch and Hazara population from Pakistan and Hazara population from Afghanistan were missing. In the current study, Yfiler Plus PCR Amplification Kit loci were examined in 260 unrelated Hazara individuals from Afghanistan, 153 Hazara individuals, and 111 Balochi individuals from Baluchistan Pakistan. For the Hazara population from Afghanistan and Pakistan overall, 380 different haplotypes were observed on these 27 Y-STR loci, gene diversities ranged from 0.51288 (DYS389I) to 0.9257 (DYF387S1), and haplotype diversity was 0.9992. For the Baloch population, every individual was unique at 27 Y-STR loci; gene diversity ranged from 0.5718 (DYS460) to 0.9371(DYF387S1). Twelve haplotypes were shared between 178 individuals, while only two haplotypes among these twelve were shared between 87 individuals in Hazara populations. Rst and Fst pairwise genetic distance analyses, multidimensional scaling plot, neighbor-joining tree, linear discriminatory analysis, and median-joining network were performed, which shed light on the history of Hazara and Baloch populations. The results of our study showed that the Yfiler Plus PCR Amplification Kit marker set provided substantially stronger discriminatory power in the Baloch population of Pakistan and the Hazara population across the Durand line.

Assessment of the forensic application of 50 Y-STR markers in a large pedigree

Short tandem repeats on the Y chromosome (Y-STRs), characterized by paternal inheritance, are valuable in forensic practice. Notably, the potential application of Y-STRs in pedigrees should be drawn upon, especially in China’s surname-concentrated natural villages. The study focused on 50 Y-STRs, including 13 rapidly mutating (RM) Y-STRs that largely constitute the current Y-STR commercial kits, and determined the differences in these Y-STRs between branches in a large pedigree and the discriminatory power of these haplotypes in different units for male relatives. As indicated in the results, 14 inconsistencies were observed at 9 Y-STRs between 10 father-son pairs. In addition, these 50 Y-STR haplotypes discriminated 10 out of 47 father-son pairs, 106 of 148 cousin pairs, 70 of 119 uncle-nephew pairs, 17 of 39 brother pairs, and 14 out of 33 grandfather-grandson pairs in a large pedigree. The RM Y-STR set is able to differentiate close male relatives in a large pedigree.

Identification and characterization of novel rapidly mutating Y-chromosomal short tandem repeat markers.

Short tandem repeat polymorphisms on the male-specific part of the human Y-chromosome (Y-STRs) are valuable tools in many areas of human genetics. Although their paternal inheritance and moderate mutation rate (~10-3 mutations per marker per meiosis) allow detecting paternal relationships, they typically fail to separate male relatives. Previously, we identified 13 Y-STR markers with untypically high mutation rates (>10-2 ), termed rapidly mutating (RM) Y-STRs, and showed that they improved male relative differentiation over standard Y-STRs. By applying a newly developed in silico search approach to the Y-chromosome reference sequence, we identified 27 novel RM Y-STR candidates. Genotyping them in 1,616 DNA-confirmed father-son pairs for mutation rate estimation empirically highlighted 12 novel RM Y-STRs. Their capacity to differentiate males related by 1, 2, and 3 meioses was 27%, 47%, and 61%, respectively, while for all 25 currently known RM Y-STRs, it was 44%, 69%, and 83%. Of the 647 Y-STR mutations observed in total, almost all were single repeat changes, repeat gains, and losses were well balanced; allele length and fathers' age were positively correlated with mutation rate. We expect these new RM Y-STRs, together with the previously known ones, to significantly improving male relative differentiation in future human genetic applications.

Investigation on rapidly mutating Y-STRs multiplex in Indian population: A pilot study

Importance of rapidly mutating (RM) Y- STRs) is already established and is evident with the addition of seven RM Y-STR markers in new generation Yfiler Plus (YFP) multiplex system. Performance of the 7 RM Y-STRs included in YFP is evaluated in central Indian population. We also report here a pilot study on genetic polymorphism using 13 Rapidly Mutating Y STRs (RM Y-STR) on Indian population. Forensic parameters including allele frequencies, gene diversities, discrimination capacity and Haplotype diversity will be calculated for both the amplification assays. Forensic application and kinship analysis will be highlighted in thisstudy.

Evaluation of rapidly mutating Y-STRs in Pakistani population

Y-chromosomal Short Tandem Repeats have been widely used in forensic investigations, identification of males for criminal justice purpose and population genetics. Commercially available Y-STRs kits allow the identification of male pedigrees and has a limited application in forensic genetics because of its limitation in differentiating closely related male individuals. Recent research with the Rapidly Mutating Y-STRs (RM Y-STRs) have revealed that these loci deliver significantly higher discrimination capacity and haplotype diversity in worldwide populations when compared with the conventional Y-STRs. Although a number of RM Y-STRs have found their way in most updated commercial kits, there are still some loci that are not yet used in such kits. The aim of this study is to develop RM Y-STR haplotypes frequency database for the Pakistani population, in order to appraise the resolution power of these loci. A total of 212 unrelated males from the Pakistani population were typed with 13 RM Y-STRs which comprise DYF399S1, DYF387S1, DYS570, DYS576, DYS518, DYS526a + b, DYS626, DYS627, DYF403S1a + b, DYF404S1, DYS449, DYS547 and DYS612. 211 unique haplotypes were identified, out of which 1 haplotype was shared between two individuals, accounting for 0.9952 discrimination capacity (DC). Haplotype diversity was found to be 0.999925. Gene diversity (GD) values of all the loci were higher than 0.5, where the highest GD values were observed at DYF399S1, DYF403S1a and DYF404S1; with values of 0.99419, 0.98252 and 0.93061 respectively. Results of our study revealed that these 13 RM Y-STRs produced significantly stronger discriminatory power in Pakistani populations.

Evaluation of 13 rapidly mutating Y-STRs in endogamous Punjabi and Sindhi ethnic groups from Pakistan.

Y-chromosomal short tandem repeats (Y-STRs) are commonly used to study population histories, discover ancestral relationships, and identify males for criminal justice purposes. Y-STRs being largely in forensic use have low haplotype diversity in some populations and cannot discriminate between paternal male relatives. Rapidly mutating Y-STRs (RM Y-STRs) were breakthrough and have been paid much attention. A set of 13 rapidly mutating (RM) Y-STRs (DYF387S1, DYF399S1, DYF403S1a/b1/b2, DYF404S1, DYS449, DYS518, DYS526I/II, DYS547, DYS570, DYS576, DYS612, DYS626, and DYS627) typically reveals higher haplotype diversities than the commercially available Y-STR sets and allows differentiating male relatives for which commercial Y-STR sets are usually not informative. Here, we amplified the 13 RM Y-STRs in 168 (37 Sindhi and 131 Punjabi) individuals from Pakistani population, which is characterized by high rates of endogamy. The haplotype diversity and discrimination capacity were 1. Allelic frequencies ranged from 0.0060 to 0.5060, while gene diversity ranged from 0.6759 (DYS526a) to 0.9937 (DYF399S1). A total 319 different alleles were observed. Results of our study showed that RM Y-STRs provided substantially stronger discriminatory power in Pakistani populations.

COULD RAPIDLY MUTATING Y-STRS BE A POTENTIAL FORENSIC TOOL IN DISCRIMINATING LEBANESE MONOZYGOTIC TWINS?

Despite the high power of discrimination that characterizes the well identified 16 to 24 autosomal short tandem repeat markers, monozygotic twins differentiation is generally limited. Arising from a single fertilized egg, monozygotic twins share the same genotype therefore the same DNA profile. This situation imposes a challenge in forensics especially considering that lineage markers are in general less informative than autosomal ones. Although in some cases Y haplotype is considered a powerful investigative tool, it cannot distinguish males belonging to the same paternal lineage. The use of rapidly mutating Y-STRs with mutation rate above 1x10-2 that were recently included in forensic casework is presumed helpful. Since science is always dynamic and each population has its own characteristics, we aim in this study to distinguish between Lebanese monozygotic male twins using rapidly mutating Y-STRs. For this purpose, fourteen unrelated pairs of male monozygotic twins were recruited. Participants filled in a well-designed questionnaire and signed an informed consent. DNA was extracted using PureLink Genomic DNA Mini kit, genotyped using the Identifiler Plus kit, and separated on 3500 Genetic Analyzer to confirm the monozygosity status. DNA samples underwent a second amplification using the Y Filer Plus kit. According to our results, all the Y Filer Plus DNA profiles showed complete match for each twin pair. By consequence, the use of rapidly mutating Y-STRs in this study did not improve discrimination.

Genetic characterisation of 13 rapidly mutating Y-STR loci in 100 father and son pairs from South and East Turkey

Background: Rapidly mutating (RM) Y-STRs recently emerged as a useful genotyping tool that can counteract problems normally associated with traditional Y-STRs. For instance, RM Y-STRs have the potential to differentiate Y-chromosomes from both close and distant paternal relatives.Aim: Characterisation of 13 RM Y-STR loci in a new sample pool from Turkey in terms of population genetic data and mutation rates.Subjects and methods: One hundred father–son pairs from South and East Turkey were genotyped. Based on the 99 father haplotypes unique to the current study, statistical parameters of forensic interest were computed. Nei’s DA distances among 112 global population datasets were estimated and visualised by phylogenetic and multidimensional scaling (MDS) analyses.Results: Fifteen father–son pairs were found to differ at a single locus and four at two loci, resulting in a differentiation rate of 19%. Mutations were observed at 10 out of 13 loci, with rates ranging from 1 × 10−2 to 6 × 10−2.Conclusion: Mutation rates and differentiation rates between the father–son pairs were similar to those from the literature. In contrast to previous work, novel phylogenetic tree construction results based on Nei’s DA distances suggested a close correlation between the geographic and genetic distances observed, except for known cases of past mass migration events.

WITHDRAWN: Corrigendum to ‘Development of an Italian RM Y-STR haplotype database: results of the 2013 GEFI collaborative exercise’ [Forensic. Sci. Int. Genet. 15 (2015) 56-63

An inconsistency in the nomenclature used for the rapidly mutating (RM) Y-chromosomal short tandem repeat (Y-STR) marker DYS449 was noted in the above paper. In this paper, the DYS449 allele nomenclature introduced by Ballantyne et al. was used, instead of that described by Redd et al. and subsequently adopted by the International RM Y-STR User Group and in the AMPFlSTR® YFiler Plus kit.

Assessment of a subset of Slowly Mutating Y-STRs for forensic and evolutionary studies

Y-specific short tandem repeat (Y-STR) loci display different mutation rates and consequently are suitable for forensic, genealogical, and evolutionary studies that require different levels of timelines and resolution. Recent efforts have focused on implementing Rapidly Mutating (RM) Y-STRs to assess male specific profiles. However, due to their high mutation rate their use in kinship testing or in phylogenetic studies may be less reliable. In the present study, a novel Slowly Mutating Y-STR (SM) panel, including DYS388, DYS426, DYS461 (Y-GATA-A7.2), DYS485, DYS525, and DYS561, has been developed and evaluated in a sample set of 628 unrelated males from different worldwide populations. This panel is reproducible, sensitive, and robust for forensic applications and may be useful in conjunction with the common multiplexes, particularly in exclusion of kinship cases where minimal discrimination is reported employing the rapidly mutating Y-STR systems. Furthermore, SM Y-STR data may be of value in evolutionary studies to optimize the resolution of phylogenetic relationships generated with current Y-STR panel sets. In this study, we provide an extensive Y-STR allele and haplotype reference dataset for future applications.

Mutation rates of 13 RM Y-STRs in a Han population from Shandong province, China

13 rapidly mutating (RM) Y-STRs in Shandong Han population were investigated to verify the mutation characteristic in order to assess the power of the STR loci to differentiate Chinese Han individuals. Using a novel multiplex PCR system, we identified 2880 alleles transferring in 180 father-son pairs at the 13 RM Y-STR loci, differentiating 19.44% of the 180 father-son pairs. Inconsistencies were observed in only four father-son pairs at two loci. 39 mutation events were observed at the 13 loci, with an average mutation rate of 0.0135 (95% CI, 0.0096–0.0185). The most rapidly mutating loci among the 13 STR loci are DYF399S1abc, DYF403S1b2 and DYS570. All mutations discovered in this study are one-step mutations. The frequency of loss to gain of repeats equals to 1.17:1.

Comprehensive mutation analysis of 53 Y-STR markers in father-son pairs

The knowledge of mutation rate at Y-STR markers is essential in forensic casework, especially kinship genetic studies. In the present study, one hundred father–son pairs from Chinese Han population were typed with 53 Y STR markers (38 conventional markers and 15 rapidly mutating markers). A total of 28 mutations were detected in 6201 allele transfers. All were one-step mutation. The average estimated mutation rate of 15 rapidly mutating (RM) Y-STRs was 1.05×10−2 (95% CI 5.45×10−3–1.39×10−2), while the average mutation rate of 38 conventional Y-STRs was 1.46×10−3 (95% CI 3.07×10−4–2.59×10−3). In summary, the average mutation rate of 15 RM Y-STRs seemed to be seven times higher than that of 38 conventional Y-STRs.