Solution to a case involving the interpretation of trace degraded DNA mixtures.

DNA mixture analysis poses a significant challenge in forensic genetics, particularly when dealing with degraded and trace amount DNA samples. Multi-SNPs (MNPs) are genetic markers similar to microhaplotypes but with smaller molecular sizes (< 75 bp), making them theoretically more suitable for analyzing degraded and trace amount samples. In this case report, we investigated a cold case involving a campstool stored for over a decade, aiming to detect and locate the suspect's DNA. We employed both conventional capillary electrophoresis-based short tandem repeat (CE-STR) analysis and next-generation sequencing-based multi-SNP (NGS-MNP) analysis. The typing results and deconvolution of the mixed CE-STR profiles were inconclusive regarding the presence of the suspect's DNA in the mixed samples. However, through NGS-MNP analysis and presence probability calculations, we determined that the suspect's DNA was present in the samples from Sect. 4-1 with a probability of 1-8.41 × 10- 6 (99.999159%). This evidence contradicted the suspect's statement and aided in resolving the case. Our findings demonstrate the significant potential of MNP analysis for examining degraded and trace amount DNA mixtures in forensic investigations.

Searching for alternative high DNA-yielding bone types for DNA analysis of aged skeletal remains.

The petrous bone contains significantly higher amounts of DNA than any other human bone. Because of highly destructive sampling and because it is not always part of the recovered remains, the need for alternative sources of DNA is important. To identify additional optimal bone types, petrous bones were compared to femurs, tali, and calcanei sampled from 66 adult skeletons from two distinct modern-era Christian cemeteries. An extraction method employing full demineralization was used to obtain DNA, real-time PCR quantification to ascertain DNA quantity and degradation, and a commercial forensic short tandem repeats (STR) PCR amplification kit to determine genetic profiles. Statistical analysis was performed to explore the differences in DNA yield, DNA degradation, and success of STR amplification. A systematic studies exploring intra-skeletal variability in DNA preservation including various excavation sites differing by time period and geographical position are rare, and the second part of the investigation was based on a comparison of both archaeological sites, which allowed us to compare the effect of different post-mortem intervals and environmental conditions on DNA preservation. The older burial site in Crnomelj was active between the 13th and 18th century, whereas the more recent Polje burial was in use from the 16th to 19th century, creating different temporal and geographical environments. Results for the Crnomelj burial site revealed that the petrous bone outperformed all other bone types studied, except the calcaneus. At the Polje archeological site calcanei, tali, and femurs yielded the same STR typing success as petrous bones. The results obtained highlight the importance of careful bone sample selection for DNA analysis of aged skeletal remains. In addition to petrous bones, calcanei were found to be an alternative source of DNA when older burial sites are investigated. When more recent burial sites are processed, calcanei, tali, and femurs should be sampled besides petrous bones, not only because they exhibited good performance, but also because of easier sampling and easier grinding in the case of trabecular bones. This study contributes valuable insights into the potential use of various skeletal types as a source of DNA for investigation of aged skeletal remains, and it offers practical implications for forensic and archaeological investigations.

Genetic polymorphism of 27 Y-STR loci in Kazakh populations from Central Kazakhstan.

BACKGROUND: The haplotypes from Northern, Southern, Eastern, and Western Kazakhstan, analysed for 27 Y-STR loci, have been contributed to the Y-Chromosome STR Haplotype Reference Database, while the genetic profile of Central Kazakhstan remains inadequately explored. AIM: To investigate the genetic diversity of 27 Y-STR loci in the Kazakh populations from Central Kazakhstan. SUBJECTS AND METHODS: A total of 112 unrelated Central Kazakh males were genotyped via the Yfiler Plus kit. Data analysis yielded haplotype and allele frequencies, and forensic parameters. Genetic distances were graphically represented by a multidimensional scaling plot, with genetic linkages further elucidated through Nei's distance dendrograms and Median-joining networks. RESULTS: A total of 102 haplotypes were detected, of which 96 were unique. The haplotype diversity and discrimination capacity were 0.997 and 0.91, respectively. Central Kazakhstan displays a unique cluster in analyses, underscoring its distinct Y-chromosome diversity compared to other Kazakh regions. The analysis of the Naiman tribe, predominantly residing in Central, Southern and Eastern Kazakhstan, revealed three genetic clusters of distinct haplogroups associated with their clans. CONCLUSIONS: The identified haplotypes will enhance the existing reference database for Y-chromosomal studies in Kazakhstan, offering a robust tool for future research in population genetics, forensic science and genetic genealogy.

An innovative approach for low input forensic DNA sample analysis using the GlobalFiler™ IQC PCR amplification Kit on the Magelia® platform.

Short Tandem Repeat (STR) markers have been the gold standard for human identification testing in the forensic field for the last few decades. The GlobalFiler™ IQC PCR amplification Kit has shown sensitivity, high power of discrimination and is therefore widely used. Samples with limited DNA quantities remain a significant hurdle for streamlined human forensic identification. Reaction volume reduction in a closed system paired with automation can provide solutions to secure DNA profiles when routine methods fall short. We automated and optimized the GlobalFilerTM IQC PCR Amplification Kit on the Magelia®, a closed molecular biology platform, to test whether reaction volume reduction in a confined automated system would improve signal and sensitivity. We evaluated the platform's performance using reference and real casework samples (blood, cigarette butt, saliva and touch DNA) in the context of a 5-fold volume reduction when compared to the routine protocol. This strategy showed distinct advantages over standard treatment, notably increased signal for lower DNA inputs. Importantly, negative casework samples through routine treatment yielded "usable" DNA profiles after amplification using this strategy. This novel approach represents a first proof of concept for a method enabling users to treat limited samples, or to partition routine samples for multiple analyses.

bistro: An R package for vector bloodmeal identification by short tandem repeat overlap.

Measuring vector-human contact in a natural setting can inform precise targeting of interventions to interrupt transmission of vector-borne diseases. One approach is to directly match human DNA in vector bloodmeals to the individuals who were bitten using genotype panels of discriminative short tandem repeats (STRs). Existing methods for matching STR profiles in bloodmeals to the people bitten preclude the ability to match most incomplete profiles and multi-source bloodmeals to bitten individuals.We developed bistro, an R package that implements 3 preexisting STR matching methods as well as the package's namesake, bistro, a new algorithm described here. bistro employs forensic analysis methods to calculate likelihood ratios and match human STR profiles in bloodmeals to people using a dynamic threshold. We evaluated the algorithm's accuracy and compared it to existing matching approaches using a publicly-available panel of 188 single-source and 100 multi-source samples containing DNA from 50 known human sources. Then we applied it to match 777 newly field-collected mosquito bloodmeals to a database of 645 people.The R package implements four STR matching algorithms in user-friendly functions with clear documentation. bistro correctly matched 99% (187/188) of profiles in single-source samples, and 62% (224/359) of profiles from multi-source samples, resulting in a sensitivity of 0.75 (vs < 0.51 for other algorithms). The specificity of bistro was 0.9998 (vs. 1 for other algorithms). Furthermore, bistro identified 79% (720/906) of all possible matches for field-derived mosquitoes, yielding 1.4x more matches than existing algorithms.bistro identifies more correct bloodmeal-human matches than existing approaches, enabling more accurate and robust analyses of vector-human contact in natural settings. The bistro R package and corresponding documentation allow for straightforward uptake of this algorithm by others.

Protein Production at the 100L Scale.

The Baculovirus Expression Vector System (BEVS) has revolutionized the field of recombinant protein expression by enabling efficient and high yield production. The platform offers many advantages including manufacturing speed, flexible design, and scalability. In this chapter, we describe the methods including strategies and considerations to successfully optimize and scale-up using BEVS as a tool for production (Fig. 1). As an illustrative case study, we present an example focused on the production of a viral glycoprotein.

Purely Endoscopic Supracerebellar Infratentorial Approach to the Pineal Region in Pediatric Population.

Pineal lesions represent less than 1% of all brain tumors (Villani et al., Clin Neurol Neurosurg 109:1-6, 2007). The abysmal location and critical neurovascular structures remain a surgical challenge, despite the advent of microneurosurgery. The classical wide surgical suboccipital craniotomy with the supracerebellar infratentorial approach, described by Sir Victor Horsley (Victor, Proc R Soc Med 3:77-78, 1910), is infamous for its considerable surgical morbidity and mortality. This was later upgraded microneurosurgically by Stein to improve surgical outcomes (Stein, J Neurosurg 35:197-202, 1971).Ruge et al. reported the first purely endoscopic fenestration of quadrigeminal arachnoid cysts via this corridor (Ruge et al., Neurosurgery 38:830-7, 1996). A cadaver-based anatomical study by Cardia et al. demonstrated the viability for endoscope-assisted techniques (Cardia et al., J Neurosurg 2006;104(6 Suppl):409-14). However, the first purely endoscopic supracerebellar infratentorial (eSCIT) approach to a pineal cyst was performed in 2008 by Gore et al. (Gore PA et al., Neurosurgery 62:108-9, 2008).Unlike transventricular endoscopy, eSCIT approach poses no mechanical risk to the fornices and can be utilized irrespective of ventricular size. More vascular control and resultant reduction in uncontrolled hemorrhage improve the feasibility of attaining complete resection, especially around corners (Zaidi et al,, World Neurosurg 84, 2015). Gravity-dependent positioning and cerebrospinal fluid (CSF) diversion aid cerebellar relaxation, creating the ideal anatomical pathway. Also, angle of the straight sinus, tentorium, and tectal adherence can often influence the choice of approach; thus direct endoscopic visualization not only counteracts access to the engorged Galenic complex but also encourages sharp dissection of the arachnoid (Cardia et al., J Neurosurg 104:409-14, 2006). These tactics help provide excellent illumination with magnification, making it less fatiguing for the surgeon (Broggi et al., Neurosurgery 67:159-65, 2010).The purely endoscopic approach thwarts the dreaded risk of air embolisms, via simple copious irrigation from a small burr hole (Shahinian and Ra, J Neurol Surg B Skull Base 74:114-7, 2013). The tiny opening and closure are rapid to create, and the smaller wound decreases postoperative pain and morbidity. Recent literature supports its numerous advantages and favorable outcomes, making it a tough contender to traditional open methods.

Prevalence of male DNA on female worn undergarments. How small datasets may support robust opinions in activity level evaluative reporting.

In cases of sexual assault, the interpretation of biological traces on clothing, and particularly undergarments, may be complex. This is especially so when the complainant and defendant interact socially, for instance as (ex-)partners or by co-habitation. Here we present the results from a study where latent male DNA on female worn undergarments is recovered in four groups with different levels of male-female social interaction. The results conform to prior expectation, in that less interaction tend to result in less male DNA on undergarments. We explore the use of these experimental data for evaluative reporting given activity level propositions in a mock case scenario. We show how the selection of different populations to represent the social interaction between complainant and defendant may affect the strength of the evidence. We further show how datasets of limited size can be used for robust activity level evaluative reporting.

Chromosomal copy number and mutational status are required to authenticate ovarian cancer cell lines as appropriate cell models.

BACKGROUND: The mutational status of ovarian cancer cell line IGROV-1 is inconsistent across the literature, suggestive of multiple clonal populations of the cell line. IGROV-1 has previously been categorised as an inappropriate model for high-grade serous ovarian cancer. METHODS: IGROV-1 cells were obtained from the Netherlands Cancer Institute (IGROV-1-NKI) and the MD Anderson Cancer Centre (IGROV-1-MDA). Cell lines were STR fingerprinted and had their chromosomal copy number analysed and BRCA1/2 genes sequenced. Mutation status of ovarian cancer-related genes were extracted from the literature. RESULTS: The IGROV-1-NKI cell line has a tetraploid chromosomal profile. In contrast, the IGROV-1-MDA cell line has pseudo-normal chromosomes. The IGROV-1-NKI and IGROV-MDA are both STR matches (80.7% and 84.6%) to the original IGROV-1 cells isolated in 1985. However, IGROV-1-NKI and IGROV-1-MDA are not an STR match to each other (78.1%) indicating genetic drift. The BRCA1 and BRCA2 gene sequences are 100% identical between IGROV-1-MDA and IGROV-1-NKI, including a BRCA1 heterozygous deleterious mutation. The IGROV-1-MDA cells are more resistant to cisplatin and olaparib than IGROV-1-NKI. IGROV-1 has a mutational profile consistent with both Type I (PTEN, PIK3CA and ARID1A) and Type II ovarian cancer (BRCA1, TP53) and is likely to be a Type II high-grade serous carcinoma of the SET (Solid, pseudo-Endometroid and Transitional cell carcinoma-like morphology) subtype. CONCLUSIONS: Routine testing of chromosomal copy number as well as the mutational status of ovarian cancer related genes should become the new standard alongside STR fingerprinting to ensure that ovarian cancer cell lines are appropriate models.

Densitometry of STR-PAGE for donor chimerism in acute leukemia's: A simple method for routine use.

Objective: To evaluate a PCR based method of polyacrylamide gel electrophoresis of short tandem repeats and its quantification for detecting donor chimerism after haematopoietic stem cell transplantation in acute leukaemias. Methods: The descriptive study was conducted at Genetic Resource Centre (GRC) Lab Rawalpindi from Feb 2018 - Nov 2020. A total of twenty patients with acute leukaemias having undergone HSCT were selected and assessed for the analysis of chimerism status. DNA extraction from the whole blood was done by chelex method and short tandem repeats were amplified by using conventional STR- PCR assay. Electrophoresis was carried out and 6% polyacrylamide gels were used for the resultant amplified DNA products and then followed by their densitometry. These patients had undergone HSCT from Pakistan Institute of Medical Science and Armed Forces Bone Marrow Transplant Centre. Results: The peaks in the PAGE densitometry represented the donor chimerism in all post transplant samples of the patients. Conclusion: Our study showed that densitometry of STR PCR PAGE is a useful and cheaper method for demonstration of donor chimerism in acute leukaemia patients having undergone HSCT. Hence this method can be a valuable option in the monitoring of chimerism status in these patients and therefore helps in preventing graft failure by fast and early treatment strategies for these patients.

Construction of 13-locus X-STR multiplex PCR system that reinforces Argus X-12 kit discrimination capacity: Application to the Malay population.

Closely linked groups of markers on the X chromosome are very useful for testing complex kinship relationships involving X-STR transmission. The Argus X-12 kit, a unique commercially available kit, can obtain haplotypes of 4 linkage groups (LGs) consisting of 3 markers. Although many population data have been reported for forensic purposes, differences in discrimination ability exist between LG1 and LG2, 3, and 4 in East Asian populations, and the data of this kit would become more useful if the discrimination ability of the latter groups were increased. Therefore, for matches found using this kit for some linkage group data, then to increase the identification ability, we additionally introduced 13 X-STR loci and established a method allowing comparison using data from 25 loci. The 13X-STRs add two locus data to each of LG2, 3, and 4, and also add two closely linked group (CLG) data between LG2 and 3 and LG3 and 4 in one multiplex PCR. Assessment of this method for a Malay population for which data by Argus X-12 had already been reported showed that the frequencies of distinct haplotypes in LG2, 3, and 4 were increased by 33.0-42.6 %, and frequencies of unique haplotypes increased by 45.4-59.2 %. The respective haplotype diversity values of the additional 3-locus and 4-locus CLGs were 0.9838 and 0.9939, which helps to improve discriminatory power and to predict recombination locations on the X chromosome. Although we have been testing these loci with Japanese subjects, this system would also be useful for the Malay population.

The Usefulness of qPCR Data for Sample Pre-Assessment and Interpretation of Genetic Typing Results.

DNA quantification is a crucial step in the STR typing workflow for human identification purposes. Given the reaction's nature, qPCR assays may be subjected to the same stochastic effects of traditional PCR for low-input concentrations. The study aims to evaluate the precision of the PowerQuant® (Promega) kit assay measurements and the degree of variability for DNA templates falling below the optimal threshold of the PowerPlex® ESX-17 Fast STR typing kit (Promega). Five three-fold dilutions of the 2800 M control DNA (Promega) were set up. Each dilution (concentrations: 0.05, 0.0167, 0.0055, 0.00185, and 0.000617 ng/µL) was quantified and amplified in four replicates. Variability for qPCR results, STR profile completeness, and EPGs' peak height were evaluated. The qPCR-estimated concentration of casework samples was correlated with profile completeness and peak intensity, to assess the predictive value of qPCR results for the successful STR typing of scarce samples. qPCR was subjected to stochastic effects, of which the degree was inversely proportional to the initial input template. Quantitation results and the STR profile's characteristics were strongly correlated. Due to the intrinsic nature of real casework samples, a qPCR-derived DNA concentration threshold for correctly identifying probative STR profiles may be difficult to establish. Quantitation data may be useful in interpreting and corroborating STR typing results and for clearly illustrating them to the stakeholders.

Genetic Diversity Based on the Analysis of 27 Y- Short Tandem Repetition (STR) Loci in Two Populations in the Apuseni Mountains, Romania.

BACKGROUND: Y chromosome analysis is used in various fields of forensic genetics, genetic genealogy, and evolutionary research, due to its unique characteristics. Short tandem repetitions (STR) are particularly relevant in population genetic studies. The aim of this study is to analyze the genetic profile of two populations in the Apuseni Mountains area, Baița and Roșia Montana, Romania. METHODS: 27 STR loci of the Y chromosome were analyzed to investigate the genetic profile of two populations from the Apuseni Mountains area. Investigating genetic diversity by analyzing allele frequency, haplotype frequency, calculating forensic parameters, and presenting the main haplogroups identified based on Y-STR markers. RESULTS: Gene diversity in the batch from Baița varies from 0.515 for the DYS393 locus to 0.947 for the DYS385 locus. In the Roșia Montana population, gene diversity ranges from 0.432 for DYS393 to 0.931 for DYS385. The haplotype diversity in Roșia Montana was 0.991, and the haplotype diversity was 1.000 in the population from Baița. A total of nine haplogroups was identified in the batch from Baița, while only seven haplogroups were observed in the batch from Roșia Montana. Both groups are based on the same five major haplogroups (E, G, I, J, and R) and the most common haplogroup is R1b in both populations. CONCLUSION: In this study, the genetic diversity of two distinct populations was assessed using genetic analyses based on different markers. Analysis of Y-STR profiles revealed significant genetic diversity in both studied groups. All haplogroups identified were similar to those present in other Romanian populations.

Nanopore sequencing of forensic short tandem repeats using QNome of Qitan Technology.

Devices of nanopore sequencing can be highly portable and of low cost. Thus, nanopore sequencing is promising in in-field forensic applications. Previous investigations have demonstrated that nanopore sequencing is feasible for genotyping forensic short tandem repeats (STRs) by using sequencers of Oxford Nanopore Technologies. Recently, Qitan Technology launched a new portable nanopore sequencer and became the second supplier in the world. Here, for the first time, we assess the QNome (QNome-3841) for its accuracy in nanopore sequencing of STRs and compare with MinION (MinION Mk1B). We profile 54 STRs of 21 unrelated individuals and 2800M standard DNA. The overall accuracy for diploid STRs and haploid STRs were 53.5% (378 of 706) and 82.7% (134 of 162), respectively, by using QNome. The accuracies were remarkably lower than those of MinION (diploid STRs, 84.5%; haploid, 90.7%), with a similar amount of sequencing data and identical bioinformatics analysis. Although it was not reliable for diploid STRs typing by using QNome, the haploid STRs were consistently correctly typed. The majority of errors (58.8%) in QNome-based STR typing were one-repeat deviations of repeat units in the error from true allele, related with homopolymers in repeats of STRs.

Reactive Oxygen Species (ROS) Measurement in Arabidopsis Guard Cells in Response to Biotic and Abiotic Stresses.

One of the major plant stress level indicators is reactive oxygen species (ROS). They have been known to play a central role in regulating plant responses to various environmental stresses. This book chapter specifically covers abiotic stress induced by a drought hormone abscisic acid and biotic stress induced by Pseudomonas syringe DC3000 on single cell-type guard cells. We describe in detail the measurement of ROS production starting from sample preparation to data analysis by fluorescence intensity acquisition using ImageJ software. We discussed the problems faced while performing the experiment and addressed how to overcome them by providing specific guidelines to ensure high quality repeatable data.

Population-genetic and comparative interpopulation studies of the 15 autosomal STR markers in the population living in the Northwest of Iran.

INTRODUCTION: Iran, a country in the Middle East, has several ethnic and ethno-religious groups and needs its own ethnic-specific databases for the forensic statistical parameters and allele frequency of STR markers. METHODS: We have investigated 600 unrelated Turk individuals from four northwestern provinces of Iran using the Identifiler™ system (TPOX, FGA, vWA, TH01, CSF1PO, D2S1338, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D19S433, and D21S11). Furthermore, STR allelic frequencies were compared to previously population-based data. RESULTS AND CONCLUSION: After Bonferroni correction, deviation from Hardy-Weinberg equilibrium (HWE) was observed in the FGA, TPOX, VWA, and D19S433 loci (P value < 0.05). The combined power of discrimination (CPD) and exclusion (CPE) values for all 15 STR loci were 0.9999999999999999999984 and 0.9999999, respectively. In comparison with Azerbaijani and Turkish populations, there were no significant differences on all STR markers. However, in the Chinese Han population, differences at 13 STR loci were detected. Additionally, comparisons of Fischer genetic distance indices (FST) P-values did not reveal any statistically significant difference between Northwestern Iran, Azerbaijan and Iran (Fars) populations. PCA and PCoA analyses showed that our population was grouped with different populations in different quarters, showing a positive and negative correlation, respectively. In the NJ and UPGMA phylogenetic trees, Iranian populations were grouped together. These results demonstrated that the given set of STR markers can be confidently used for all identification tests in Northwestern Iran.

Zygotic-splitting after in vitro fertilization and prenatal parenthood testing after suspected embryo mix-up - a case report.

After in vitro fertilization with a single embryo, the parents learned about being pregnant with twins in the 10th week with various indications that an embryonic mix-up could have taken place. The affected couple thus expressed the urgent desire for a clarification of parenthood considering an abortion. However, the prenatal test results would not have been available until the 14/15th week of pregnancy. Legally, then, severe physical or mental distress of the pregnant woman must be claimed by physicians to justify an abortion after the twelfth week. However, a lack of genetic relatedness could lead to serious psychological distress for the parents, making a pregnancy termination possible even after the twelfth week, which is discussed in this case study alongside the interdisciplinary team's ethical, legal, and medical considerations.For the invasive relationship testing, cultivated chorionic villi samples (CVS) from both unborn and saliva samples from the putative parents were genetically analyzed using classical short tandem repeats (STR) analysis. The perfect match of both CVS profiles suggested the occurrence of an unusual late twin shaft, for which, fortunately, parenthood could be confirmed. To our knowledge, this is the first report on a prenatal investigation of a suspected embryo mix-up after assisted reproductive technology (ART), in which parenthood should be fixed. We want to draw attention to this unthinkable scenario, which may increase in the future with ART-induced rising multiple pregnancies.

Preimplantation Genetic Diagnosis of Androgen Resistance Syndrome Caused by Mutation on the AR Gene in Vietnam.

Background: Androgen resistance syndrome or androgen insensitivity syndrome (AIS - Androgen Insensitivity Syndrome, OMIM 300068) is an X-linked recessive genetic syndrome causing disorders of sexual development in males. This disease is caused by mutations in the AR gene located on the X chromosome, which encodes the protein that structures the androgen receptor, with the role of receiving androgens. Mutation of the AR gene causes complete or partial loss of androgen receptor function, thereby androgen not being obtained and exerting its effect on target organs, resulting in abnormalities of the male reproductive system due to this organ system, differentiating towards feminization under the influence of estrogen. Disease prevention can be achieved by using pre-implantation genetic diagnosis, which enables couples carrying the mutation to have healthy offspring. Aim: To carry out preimplantation genetic diagnosis of androgen resistance syndrome. Methods: Sanger sequencing was used to detect the mutation in the blood samples of the couple, their son, and 01 embryo that were biopsied on the fifth day based on the findings of next-generation sequencing (NGS) of the affected son. We combined Sanger sequencing and linkage analysis using short tandem repeats (STR) to provide diagnostic results. Results: We performed preimplantation genetic diagnosis for AIS on an embryo from a couple who had previously had an affected son. Consequently, one healthy embryo was diagnosed without the variant NM_000044: c.796del (p.Asp266IlefsTer30). Conclusion: We report on a novel variant (NM_000044: c.796del (p.Asp266IlefsTer30)) in the AR gene discovered in Vietnam. The developed protocol was helpful for the preimplantation genetic diagnosis process to help families with the monogenic disease of AIS but wish to have healthy children.

Case reports on uniparental disomy of chromosomes 6 and 3 in paternity testing.

In paternity testing, when there are Mendelian errors in the alleles between the child and the parents, a slippage mutation, or silent allele may not fully explain the phenomenon. Sometimes, it is attributed to chromosomal abnormalities, such as uniparental disomy (UPD). Here, we present the investigation of two cases of suspected UPD in paternity testing based on short tandem repeat (STR) detection (capillary electrophoresis platform). Case 1 involves a trio, where all genotypes detected on chromosome 6 in the child are homozygous and found in the father. Case 2 is a duo (mother and child), where all genotypes on chromosome 3 in the child are homozygous and not always found in the mother. At the same time, Mendelian error alleles were also observed at specific loci in these two chromosomes. Furthermore, we used the MGIEasy Signature Identification Library Prep Kit for sequencing on the massively parallel sequencing platform, which included common autosomal, X and Y chromosomes, and mitochondrial genetic markers used in forensic practice. The results showed that the genotypes of shared STRs on the two platforms were consistent, and STRs and single nucleotide polymorphisms (SNPs) on these two chromosomes were homozygous. All other genetic markers followed the laws of inheritance. A comprehensive analysis supported the parent-child relationship between the child and the alleged parent, and the observed genetic anomalies can be attributed to UPD. UPD occurrences are rare, and ignoring its presence can lead to erroneous exclusions in paternity testing, particularly when multiple loci on a chromosome exhibit homozygosity.

[Authenticity and adulteration identification of Bubali Cornu based on DNA fingerprints].

Whether adulteration exists is a difficult problem in the identification of traditional Chinese medicine(TCM). Bubali Cornu is mainly available in the medicinal material market in the form of buffalo horn silk or buffalo horn powder but lacks obvious identification characteristics, so there is a risk of adulteration. However, the method of identification of adulteration in Bubali Cornu is lacking at present. In order to ensure authenticity and identify adulteration of TCM Bubali Cornu, control the quality of TCM Bubali Cornu, and ensure the authenticity of clinical use, the DNA fingerprints of 43 batches of samples from pharmaceutical companies and medicinal material markets were identified, and the amplification primers of fluorescent DNA fingerprints of Bubali Cornu and Bovis Grunniens Cornu were screened. The DNA fingerprints of Bubali Cornu were obtained by fluorescent capillary typing. The identification effect of fluorescent capillary typing on different adulteration ratios was also tested. Two pairs of fluorescent STR typing primers, namely 16Sa and CRc, which can distinguish Bubali Cornu and Bovis Grunniens Cornu, were screened out, and a DNA fingerprint identification method was established. The 16Sa migration peaks of Bovis Grunniens Cornu and Bubali Cornu were 223.4-223.9 bp and 225.5-226.1 bp. The CRc migration peaks of Bovis Grunniens Cornu and Bubali Cornu were 518.8-524.8 bp and 535.9-542.5 bp. The peak height of the migration peak could be used for preliminary quantification of the adulterants with an adulteration ratio below 50%, and the quantitative results were similar to the adulteration ratio. In this study, a simple and quick universal DNA fingerprint method was established for the identification of Bubali Cornu and its adulterants, which could realize the identification of TCM Bubali Cornu and the semi-quantitative identification of the adulterants.