Genetic polymorphism and phylogenetic analysis of 15 autosomal STR markers in the Santal indigenous population of Bangladesh

Fifteen autosomal STR markers, namely D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818, and FGA were typed using AmpFlSTR® Identifiler® Plus PCR amplification systems in 132 unrelated Santal individuals of Bangladesh. Forensic efficiency parameters like, matching probability (MP), power of discrimination (PD), polymorphism information content (PIC), power of exclusion (PE), typical paternity index (TPI), observed heterozygosity (Hobs), and expected heterozygosity (Hexp) were calculated for all the loci. No deviations from Hardy-Weinberg equilibrium were detected for the loci after Bonferroni correction. The combined matching probability (MP), combined power of discrimination (PD) and combined power of exclusion (PE) for the 15 tested STR markers were 8.38 x 10-17, 0.999999998 and 0.0.999993866, respectively. A comparison of the locus wise allele frequencies of autosomal STR data of the Santal population with the published geographically close population data based on Nei’s genetic distance revealed that the Santal population is closely related to Munda population from Jharkhand, India. Bioresearch Commu. 7(2): 1004-1009, 2021 (June)

Noninvasive Prenatal Paternity Testing with a Combination of Well-Established SNP and STR Markers Using Massively Parallel Sequencing

Cell-free fetal DNA (cffDNA) from maternal plasma has made it possible to develop noninvasive prenatal paternity testing (NIPPT). However, most studies have focused on customized single nucleotide polymorphism (SNP) typing systems and few have used conventional short tandem repeat (STR) markers. Based on massively parallel sequencing (MPS), this study used a widely-accepted forensic multiplex assay system to evaluate the effect of noninvasive prenatal paternity testing with a combination of well-established SNP and STR markers. Using a ForenSeq DNA Signature Prep Kit, NIPPT was performed in 17 real parentage cases with monovular unborn fetuses at 7 to 24 gestational weeks. Different analytical strategies for the identification of paternally inherited allele (PIA) were developed to deal with SNPs and STRs. Combined paternity index (CPI) for 17 real trios as well as 272 unrelated trios was calculated. With the combination of SNPs and A-STRs, 82.35% (14/17), 88.24% (15/17), 94.12% (16/17), and 94.12% (16/17) of real trios could be accurately determined when the likelihood ratio (LR) threshold for paternity inclusion was set to 10,000, 1000, 100, and 10, respectively. This reveals that simultaneous surveys of SNP and STR markers included in the ForenSeq DNA Signature Prep Kit offer a promising method for NIPPT using MPS technology.

On the mutation model used in the fingerprinting DNA

ObjectivesThe most common technique of determining biological paternity or another relationship among people are the investigations of DNA polymorphism called Fingerprinting DNA. The key concept of these investigations is the statistical analysis, which leads to obtain the likelihood ratio (LR), sometimes called the paternity index.MethodsAmong the different assumptions stated in these computations is a mutation model (this model is used for all the computations).Results and conclusionsAlthough its influence on LR is usually negligible, there are some situations (when the mother–child mutation arises) when it is crucial.

Twins from different fathers: A heteropaternal superfecundation case report in Colombia

Heteropaternal superfecundation is an extremely rare phenomenon that occurs when a second ova released during the same menstrual cycle is additionally fertilized by the sperm cells of a different man in separate sexual intercourse.In August, 2018, the Grupo de Genética de Poblaciones e Identificación at Universidad Nacional de Colombia received a request to establish the paternity of a pair of male twins with genetic markers. The following analyses were performed: amelogenin gene, autosomal short tandem repeat (STR), and Y-STR analyses by means of human identification commercial kits, paternity index, and the probability of paternity calculation and interpretation. A paternity index of 2.5134E+7 and a probability of paternity of 99.9999% for twin 2 were obtained while 14 out of 17 Y-chromosome markers and 14 out of 21 autosomal short tandem repeats were excluded for twin 1. The results indicated that the twins have different biological fathers.Although heteropaternal superfecundation is rarely observed among humans given its low frequency, in paternity disputes for dizygotic twins it is mandatory to demand the presence of the two twins in the testing to avoid wrong conclusions.

Contribution of ABO-Rhesus/Electrophoresis of hemoglobin methods and Short Tandem Repeats analysis in the determination of paternity in Burkina Faso, West Africa

Background: the establishment of filiation by the current ABO, HLA, MNS, Kells and serum tests, pose a real reliability problem. It is then necessary to combine these methods with or to use high-performance methods such as microsatellite genetic analysis or short tandem repeats. This study aimed to compare the short tandem repeat technique with ABO/Rhesus system in combination with electrophoresis of hemoglobin. Methods: Fourteen (14) contested paternity trios were investigated. Blood samples were collected to determine blood groups using the Beth-Vincent method and the type of hemoglobin by electrophoresis. Blood spots on FTA paper were used for the analysis of 16 STR loci (D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818, FGA, Amel) by capillary electrophoresis on the ABI 31310 Genetic Analyzer. The generated sequences were analyzed with GeneMapper® software version 3.2.1. The data were analyzed to determine the paternity index and the probability of paternity. Results: Of the fourteen (14) trios studied, ten (10) cases were probable inclusion, three (03) cases were exclusion and one (01) case was an undetermined paternity outcome with the ABO-Rhesus/ electrophoresis of hemoglobin system. While the analysis of genetic polymorphisms in DNA gave five (05) inclusions versus nine (09) exclusions of paternity. Of the 10 probable inclusion cases given by the ABO-Rhesus/Electrophoresis of hemoglobin system, only 05 cases (50%) were confirmed for inclusion by Short tandem repeat analysis. Conclusion: The analysis of short tandem repeat with sixteen genetic markers is more reliable in determining paternity than ABO-Rhesus/hemoglobin electrophoresis techniques.

SHORT TANDEM REPEATS (STRs) AS A PRIMARY METHOD FOR PERSONAL IDENTIFICATION (A Case Report)

Abstrak: Mayat seorang perempuan tak dikenal yang ditemukan di daerah Malalayang dibawa oleh polisi ke Rumah Sakit Umum Pusat Prof.dr.R.D Kandou. Mayat tersebut telah mengalami proses awal pembusukan. Selain itu pihak kepolisian mengalami kesulitan untuk menentukan identitas mayat tersebut serta menemukan keluarganya. Demi pengungkapan kejadian yang menyebabkan kematian perempuan tak dikenal ini, terlebih dahulu polisi harus dapat menentukan identitas mayat. Melalui data medis yang dikumpulkan dari proses autopsi forensik, digabungkan dengan daftar orang hilang yang dibuat oleh kantor kepolisian Sektor Malalayang dan Kepolisian Kota Besar Manado, ditemukan kecocokan data yang merujuk pada seorang perempuan yang dilaporkan hilang oleh keluarganya. Polisi kemudian meminta pemeriksaan identifikasi melalui metode analisis DNA untuk membandingkan DNA mayat dengan DNA individu-individu yang mengaku sebagai keluarga korban. Pada saat autopsi forensik, diambil sampel tulang padat iga kanan dan kiri sepanjang 10 cm dari mayat. Sebagai pembanding diambil apusan mukosa pipi dan 2 cc darah tepi dari individu-individu yang diduga ayah dan adik kandung dari mayat yang ditemukan. Proses ekstraksi, kuantifikasi, PCR, dan proses analisis akan dilakukan di Pusat Laboratorium Forensik Kepolisian Republik Indonesia. Kata kunci: identitas mayat, identifikasi DNA, PCR, STR. Abstract: Ms X’s corpse was brought to Prof.R.D Kandou general hospital by police officers. Ms X was found in Malalayang without any identity attached to her body. Her body had begun to decompose, and the police had difficulties in finding Ms X’s relatives. In order to uncover the case behind Ms X’s death, the police had to first discover the true identity of Ms X. Medical data was acquired during an autopsy, and from a list that the police made, a match was found in a report of missing persons when two data were compared. The Police requested a paternity DNA examination in order to have a positive identification of Ms X. During the forensic autopsy of Ms X, 10 cm of left and right costal compact bones were obtained. Buccal swabs were made and 2 cc of peripheral blood were taken, each from the suspected father and a suspected sister of Ms X. Extraction, quantification, PCR, and the analysis was made at Pusat Laboratorium Forensik Kepolisian Republik Indonesia the main Police Forensic Laboratory of Indonesia. PCR involves 13 to 15 of nuclear STR loci, and the analyzing process of the samples involves comparing the 13 to 15 nuclear STR loci of the 3 people. If a match is found with 99% accuracy, then identification is verified. The Paternity Index indicates the greatest possibility that the suspected father is the real father of Ms X, compared to other males in the Asian / Indonesian Population.1 Keywords: corpse identity, DNA identification, PCR, STR.