Calculation of the Paternity Index for the Alleged Father Related to the Child's Mother / 法医学杂志

OBJECTIVES@#To derive the paternity index (PI) calculation formula of the alleged father (AF) when the AF is a relative (parent/child, siblings, grandparent/grandchild, uncle/nephew, first cousins) of the child's biological mother.@*METHODS@#For the case when the AF is related to the child's biological mother, the existence of the relationship in the numerator and denominator hypothesis of PI was considered. The genotype frequency of the AF was calculated by using the frequency formula in which the mother's genotype was considered, while the random male in the denominator was substituted as another relative of the mother's same rank. The PI calculation formula was derived to eliminate the effect of the relationship between AF and the child's biological mother.@*RESULTS@#When the AF and the biological mother have first, second and tertiary kinship, a more conservative PI was obtained from the PI calculation formula derived in this study compared with the PI calculation method which did not consider kinship.@*CONCLUSIONS@#The calculation method provided in this study can eliminate the effect of the relation of the AF and mother on the PI in incest cases, to obtain more accurate and conservative identification conclusions.

Influence of uniparental disomy on the conclusion of paternity testing / 中华医学遗传学杂志

Objective@#To explore the influence of uniparental disomy (UPD) on bipartite and tripartite paternity testing.@*Methods@#Two cases of paternity testing were analyzed by multiplex amplification and capillary electrophoresis typing. Suspected UPD was verified by using single nucleotide polymorphism array (SNP array). Parental power index was calculated by using a bipartite or tripartite model.@*Results@#The two cases were found to harbor respectively three short tandem repeats on chromosome 2 and two short tandem repeats on chromosome 15. SNP array verified that both cases were of UPD. Case 1 had a parental power index of 122274987565.23 by a tripartite model, while case 2 had a parental power index of 13500.8463 by a bipartite model. Based on the technical specification, the conclusions supported a biological parent-child relationship in both cases.@*Conclusion@#UPD may lead to misjudgment of paternity testing. The possibility of UPD should be considered when certain loci which do not conform to Mendelian inheritance have aggregated to one chromosome.

Comprehensive application of multiple methods in determination of half-sibling relationship / 中国法医学杂志

Objective To identify the half-sibling relationship by comprehensive using three different methods. Methods STR genotype was performed on A, A's mother, B and B's mother by using PowerPlex21 kit, AGCU Expressmarker 21+1 kit, Microreader 23sp-B kit and AGCU X-19 STR kit respectively. Based on the results of STR genotype and X-STR, we determined half-sibling relationship by ITO, discriminant function analysis and IBS. Results HIS was between 1.36×102and 2.09×105in ITO which indicated that A and B had the same father. The IBS and discriminant function analysis also had the same conclusion. Conclusion Comprehensive using multiple methods can obtain reliable result to identify the half-sibling relationship from the same father.

Risk analysis on duo paternity tests / 中国法医学杂志

Objective To discuss the risk in duo paternity testing. Methods 22 fictitious duo families formed by 22 pairs of unrelated individuals having one or zero inconsistent locus were selected after detected by GoldeneyeTM 20A Kit. The 22 fictitious duo families were further tested with STRtyper-10G kit and/or AGCU 21+1 STR kit until there were more than 3 inconsistent loci and the cumulative paternity index(CPI) value was less than 0.0001. According to the three excluding rules, ① number of inconsistent loci>3; ② CPI ≤ 0.0001; ③ accord with both ① and ② , using multiple STR systems, such as 19 STR loci, 26 STR loci, 39 STR loci and 46 STR loci to test and discuss whether there is difference among the excluding result of unrelated individual. Results Among those 22 fictitious duo families, using three excluding rules, None was excluded by 19 STR loci, and all was excluded by 39 STR loci. Conclusion Duo paternity tests may get a wrong result using only 19 loci system. To reduce the error risk 39 STR-loci systems would be suggested.

Genetic polymorphisms of 19 STR loci in han popu-lation from Hainan and its application in paternity testing / 中国法医学杂志

Objective To construct a database for the genetic polymorphism of 19 STR loci in Han population from Hainan province. To investigate the application of 19 STR loci in the paternity testing. Methods The genotypes of 462 unrelated individuals in Hainan were detected with GoldeneyeTM 20A PCR Amplification Kit. 19-STR database was acquired, analyzed and evaluated in 283 paternity testing cases. Results No deviations of allele frequency from Hardy-Weinberg equilibrium expectations were found for Chi-square test (P>0.05). Observed heterozygosity (Hobs) varied between 0.603 and 0.914, total discrimination power (TDP) of 19 STR loci was more than 0.999999999999999, cumulative probability of exclusion (CPE) for triplet cases was 0.999999994. In all 283 paternity testing cases, triplets and duos were 170 and 113 respectively; there were 36 (12.7%) excluded cases comparing to 247 confirmed cases (87.3%). 14 mutation events were observed, and all were one-step mutation. Conclusion 14 out of 19 loci showed highly polymorphic in Han population from Hainan, and 19 STR system has high cumulative probability of exclusion and can meet the needs of paternity test of the local region. But mutation should be paid special attention to.

An analysis of mutations at 41 short tandem repeat loci in Han Chinese population / 中国法医学杂志

Objective The aim of this study was to investigate mutations of 41 STR loci. Methods 4546 bloodstain samples were typed from 1932 father–mother–child trios by using AGCU_21+1, AGCU_EX22 and GlobalFiler_ExpressTM amplification Kit. Calculate the mutation rates of STR loci. Results 154 mutations were identified at 32 of the 41 loci. The average mutation rate was 1.0×10-3per locus(95%CI: 0.8~1.1×10-3), and the mutations of SE33 was highest. 152(98.7%) mutation events were one-step mutation, 2(1.3%) events were two-steps. The mutation events occurred in 150 father–mother–child triplets. The mutations in 146(97.3%) triplets occurred at single locus, 8 mutations were observed at two loci in 4(2.7%) triplets simultaneously. 104 paternal and 22 maternal mutations could be determined under 79212 paternal and maternal allelictransfers. The ratio of paternal versus maternal mutations was 4.7:1, and 28 unassigned mutations were observed. Conclusion STR mutation are common in paternity testing, and we should pay more attention to it.

Analysis of mutation of 20 autosomal short tandem repeat loci in Henan Han population / 中国法医学杂志

Objective To investigate the mutation phenomenon of 20 autosomal STR loci in Henan Han population. Methods A total of 3011 parentage confirmed cases were collected to screen mutation events, ascertain the source of mutation, calculate mutation rate, analyze mutation rules and compare with the mutation condition of populations in different regions. Results 76 mutation events were observed in 19 STR loci, the average and accumulative mutation rate reached to 0.08% and 1.6629%, respectively. The ration of paternal versus maternal mutation was 8:1. Mutation rates of Penta E and D12S391 loci in Henan Han population were lower than the Han population of northern China(P<0.05); the mutation rate of CSF1PO locus were lower than Guangdong population and Yunan Han population(P<0.05); the mutation rates of D6S1043 and D12S391 loci were lower than Guangdong population(P<0.05). Conclusion STR mutation events were common in paternity testing. Region differences among mutation rate were significant.

The Research Progress of Application of Epigenetics in Forensic Science / 昆明医科大学学报

Epigenetics is the study of heritable changes in gene expression other than the changes in the underlying DNA sequence. Such changes include DNA methylation,genomic imprinting,X chromosome inactivation and non-coding RNA regulation. Recent progresses on epigenetics offer new ideas to tackling these problems in forensic science,including determination of the necessary allele in paternity,identification of fetal paternity testing in embryonic period,discrimination of identical twins,origination analysis of tissue,and individual age estimation. This review focuses on the main concept of epigenetics and its application in the field of forensic science.

Genetic Polymorphism of 20 Autosomal STR Loci in Yunnan Han Popolation / 昆明医科大学学报

Objective To study the genetic polymorphism of 20 autosomal short tandem repeats(STR)loci in Yunnan Han population. Methods The 20 STR loci(D3S1358,D1S1656,D6S1043,D13S317,Penta E,D16S539,D18S51,D2S1338,CSF1PO,Penta D,TH01,vWA,D21S11,D7S820,D5S818,TPOX, D8S1179,D12S391,D19S433 and FGA)which were included in the PowerPlexR21 System kit were genotyped in 1085 unrelated Han individuals living in Yunnan province using multiplex amplication. PCR products were separated and analyzed by the AB 3130 automatic genetic analyzer and GeneMapper ID v3.2 software. Forensic parameters of each locus were calculated by Modified-Powerstates software. Results All the studied loci except for TH01 and TPOX were highly polymorphic. The observed heterozygosity(Ho)ranged from 0.6130 to 0.8743. Match probability(PM)ranged from 0.0179 to 0.2030. Power of discrimination(DP)ranged from 0.7970 to 0.9821. Probability of exclusion(PE)ranged from 0.3067 to 0.7432. Paternity index(PI)ranged from 1.2919 to 3.9766. Polymorphism information content(PIC)ranged from 0.5598 to 0.8958. No deviation of the Hardy-Weinberg equilibrium was observed. Conclusion The studied 20 STR loci were highly polymorphic in Yunnan Han population and could be used in forensic individual identification and paternity testing practice.

Cell-free fetal nucleic acid in maternal plasma and noninvasive prenatal paternity testing / 中国法医学杂志

In recent years, the cases of prenatal paternity testing gradually increased in forensic practice. The traditional prenatal paternity analysis can be performed only after invasive sampling of chorionic villi or amniotic fluid, which can result in a risk of miscarriage. The existence of circulating cell-free fetal nucleic acid in maternal plasma has brought new opportunities for the noninvasive prenatal paternity testing. In this paper, the research situation and application prospect of circulating cell-free fetal nucleic acid in maternal plasma in prenatal paternity testing are reviewed.

Aspectos bioéticos en el ejercicio actual de la genética humana / Bioethical aspects in current human genetics

En los últimos años las ciencias de la vida y la salud han conseguido hitos importantes permitiendo el surgimiento la ingeniería genética, la genética médica y la genómica, ramas que plantean la necesidad de criterios científicos y técnicos basados en la conducta y labor de sus profesionales. Es así que consideramos importante reflexionar desde el punto de vista bioético los siguientes temas: Las pruebas de paternidad, que tienen como objeto determinar el vínculo genético ascendente en primer grado entre un individuo y su progenitor masculino. El tamiz de portadores que se utiliza para determinar si una persona es portadora de una enfermedad genética, suele aplicarse a heterocigotos para un gen recesivo, en reordenamientos cromosómicos. La eugenesia, concebida como una ideología social, como ciencia es la rama de la manipulación genética que estudia el perfeccionamiento de la especie humana. La clonación humana, ha demostrado que se puede reprogramar una célula diferenciada de un individuo adulto, convirtiendo una célula altamente especializada en un embrión y hacerla volver atrás en su programa genético, obteniendo así un ser idéntico al primero. Como profesionales de la salud preservamos la vida, sin olvidar que debemos tratar de ofrecer una adecuada calidad de la misma a nuestros pacientes y dentro de condiciones éticas.

Nowdays, the life and health sciences have achieved significant milestones allowing the emergence of new branches, such as genetic engineering, molecular genetics, medical genetics and genomics, which pose scientific and technical criteria to sort and conduct their professional work. Thus, we consider important to analyze and reflect from the bioethical standpoint advances in the field of human genetics, addressing the following topics: Paternity tests, studies that are intended to determine the genetic link up (kinship) in the first degree between an individual and his male parent. The carrier screening used to determine whether a person is a carrier of a genetic disease, usually applied to individuals heterozygous fora recessive gene, or individuals heterozygous fora dominant gene that do notexpress the disease and chromosomal rearrangements. Eugenics, conceived as a social ideology, is defined as improving a species, as a science is the branch of genetic engineering that studies the improvement of the human species. Human cloning is a topic that generates more discussion not only from an ethical view, but also philosophical and religious points of view, since it has been shown that you can reprogram a differentiated cell of an adult, becoming a highly specialized cell into an embryo and make it go back in their genetic program, thus obtaining identical to the first one. As health professionals, we try to preserve life, not forgetting that we should give adequate quality of life to our patients with ethical conditions.

Study on STR Genotyping of Cell Free DNA in Plasma / 昆明医科大学学报

Objective The purpose of this study was to investigate the feasibility of short tandem repeat(STR) genotyping of cell free DNA in plasma for individual identification and paternity testing. Methods EDTA-Na2 DNA anti-coagulant blood samples were collected from 36 unrelated healthy volunteers,and both DNA in leukocytes and cell free DNA in plasma were extracted respectively using phenol-chloroform method. Target DNA in blood cells and plasma were amplified using regular STR typing and fluorescent multiplex STR assay separately,accordingly,the PCR products were analyzed by polyacrylamide gel electrophoresis and capillary electrophoresis. Results Using either normal PCR-STR or fluorescent multiplex STR assay,the consistent STR genotyping results were detected with similar efficiency for cell DNA and plasma DNA samples from the same individual. Conclusion Cell free DNA in plasma samples can be used as useful biological samples for STR genotyping,which can be applied to individual identification and paternity testing in forensic practice.

Analysis of seven STR human loci for paternity testing by microchip electrophoresis

The aim of this work was to evaluate two paternity cases by microchip electrophoresis and the validation of the methodology by comparison of the results with those obtained in a commercial genetic analyzer. It was observed that when working with tetranucleotide regions, in which the minimal difference between the alleles was only four base pairs, the commercial microchip system did not present the resolution and repeatability needed. Nevertheless, the relative standard deviation was between 0 and 1.2% and the fragments detected were within the expected size ranges as described in the literature.

Observation and Analysis of Mutation of 24 Short Tandem Repeat Loci / 中山大学学报(医学科学版)

[Objective] To analyze the phenomena and characteristics of the mutations in 24 short tandem repeat (STR) loci. [Methods] A total of 5 084 parentage confirmed cases were analyzed. The mutation events were screened. The sources of mutant alleles were ascertained. The mutation rates of STR loci were calculated. The rule and feature of mutation were analyzed. [Results] A total of 172 mutation events were observed in 24 STR loci. The mutation rate was between 0-0.492%. The number of mutation loci was between 1 and 3 for 1 case. The mutation model was accordant with stepwise mutation model. The maximum mutation step was four. In addition, the ratio of paternal versus maternal mutation was 3.55:1. [Conclusion] STR mutation events were common in paternity testing. The information of mutated STR loci should be considered and included when calculating PI value.

Establishment and Application of 18-STR Database in Han Population from Zhejiang Province / 中山大学学报(医学科学版)

[Objective] To construct a database for the genetic polymorphism of 18 STR loci (D8S1179, D21S11, D7S820, CSFIPO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, VWA, TPOX, D18S51, D5S818, FGA, PentaE, PentaD, SE33) in Hart population from Zhejiang province. To investigate the application of 18 STR loci in the field of paternity testing and prenatal diagnosis. [Methods] Fluorescent dye labeling multiplex STR-PCR, capillary electrophoresis and DNA sequencer GeneScan were adopted in genotyping 598 unrelated samples collected from Han population in Zhejiang province. 18-STR database was established and analyzed. Population comparison was conducted between Han population in Zhejiang province and 8 other population. 15-STR and 18-STR identification system were compared in 497 paternity testing cases. [Results] We observed the distribution of 18 STR loci in Han population meet Hardy-Weinberge equilibrium and was different from other 8 population (X~2 test, P>0.05). Statistical results showed that the heterozygosis (He) ranged from 0.630 to 0.942. The combined power of discrimination was>0.9999999999. Compared with 15-STR identification system, higher paternity index scores and higher exclusion rate were obtained with 18-STR identification system in dual-case paternity test and mutation identification. One trisomy 21 fetus was found in a prenatal paternity test case which had two characteristic genotypes in 2 STR loci of D21S11 and Penta D. [Conclusions] The 18 loci were relatively highly genetic polymorphic in Zhejiang Han population and could be used for paternity testing. Some STR loci could be used in prenatal diagnosis for aneuploidy.

Genetic Polymorphism Analysis of Nine Short Tandem Repeat Loci in Han Population of Southern China / 中山大学学报(医学科学版)

[Objective] To investigate the genetic polymorphism of nine short tandem repeat (STR) loci in Han population of Southern China.[Methods] The 9 STR loci (D11S2368,D12S391,D13S325,D18S1364,D22-GATA198B05,D6S1043,D2S1772,D7S3048,D8S1132) were amplified with STR＿Typer＿10＿v1 kit for 1619 unrelated individuals of Han population in Southern China.The PCR products were analyzed with 3100 genetic analyzer and GeneMapper ID 3.1v software.The forensic efficiency parameters were calculated by PowerState V12.xls and the Hardy-Weinberg equilibrium was tested with Arlequin 3.11v software.[Results] The genetic polymorphism of 9 STR loci in Han population of Southern China was quite high.The heterozygosities (H) ranged from 0.818 to 0.879.The match probabilities (MP) ranged from 0.031 to 0.063.The powers of discrimination (PD) ranged from 0.937 to 0.970,the probabilities of exclusion (PE) ranged from 0.632 to 0.753,the polymorphism information contents (PIC) ranged from 0.80 to 0.88 and the typical paternity indices (TPI) ranged from 2.74-4.13,respectively.These data were in accord with Hardy-Weinberg equilibrium (P ＞ 0.05).[Conclusion] Nine STR loci are highly polymorphic in Chinese Han population.They are new useful tools for paternity testing,individual identification,and for the research of human genetics and anthropology.

Diversidade genética e eficiência de DNA microssatélites para o controle genealógico da raça Nelore / Genetic diversity and efficiency of DNA microsatellites for genealogic control in Nelore breed

Foram estimados na raça Nelore a variabilidade genética e os valores de determinação de paternidade usando-se 11 marcadores microssatélites do painel ISAG/FAO. Estes foram organizados em quatro conjuntos de amplificação para genotipagem semi-automática por fluorescência. Todos os marcadores apresentaram-se altamente polimórficos, com média de 8,2 alelos por loco. A heterozigosidade observada, com média de 0,48, foi menor que a esperada em 10 locos. Foram observadas deficiências de heterozigotos em nove locos, o que resultou no desequilíbrio de Hardy-Weinberg para a população estudada. O conteúdo polimórfico informativo foi superior a 0,5 em 10 locos. O poder de discriminação foi >0,999 e as probabilidades de exclusão de paternidade quando são conhecidos os genótipos de um bezerro, sua mãe e um pai alegado, ou quando um ou outro genótipo parental não está disponível, para o conjunto de marcadores foram >0,999 e >0,989, respectivamente. O conjunto de 11 marcadores constitui método eficiente para a determinação de paternidade na raça Nelore

The genetic variability and paternity testing values in Nelore breed were estimated using 11 ISAG/FAO microsatellites. The markers were organized into 4 amplification groups for semi-automated fluorescence genotyping. All markers were highly polymorphic, with an average of 8.2 alleles per locus. With a mean value of 0.48, the observed heterozygosity was lower than the expected for 10 of the loci. A significant deficit of heterozygotes was observed for 9 loci, resulting in a lack of Hardy-Weinberg equilibrium in the studied population. Polymorphism information content values exceeded 0.5 for 10 loci. The power of discrimination was >0.999 and paternity exclusion probabilities when a mother, her offspring and a putative sire are compared or when one or other parental genotype is unavailable for the combined set of markers were, respectively, >0.999 and >0.989. The set of 11 microsatellite markers proved to be an efficient tool for paternity testing in Nelore cattle

Reflection on the Ethical Issues Related to Paternity Testing / 中国医学伦理学

There is no defined legislation on paternity testing in present China,thus the testing status quo is in a mess to some extent.Together with other unfavorable factors including the unstable marital status in modern society,increasing extramarital sexual behaviors and illegitimate children,and the ever-heated testing competition among testing institutes driven by the economic interests and so forth,the paternity testing is on a sharp rise these years,which leads to a increasing chaos in paternity testing field.Social ethical crisis is partially responsible for the current problem,thus related ethical issues to paternity testing are discussed in this article.

Ethical and Legal Issues Involved in Paternity Testing / 中国医学伦理学

Paternity testing has to be cautiously practiced,since it involves issues coming from all aspects including ethics,legislation,family and society.If the educational backgrounds of the litigants prevent them from fully understanding the ethical and legal issues involved in paternal testing,it would thus be impossible to achieve a real "informed consent" for the litigants.It is our point of view that in these cases,and when no alternative solutions are available,it is the responsibility of those who perform paternity testing to advise the litigants give up the application for paternity test.Besides,it is time for judicial departments to place on the agenda the establishing of a technique standard for paternity testing and relevant judicial procedures,in order to protect the basic rights of informal consent and autonomy of litigants in paternity testing practices.It is in this article that some ethical and legal issues commonly involved in paternity testing are discussed.

PATERNITY TESTING BY ANALYSIS OF THREE VNTR GENETIC MARKERS / 中国法医学杂志

The polymorphisms of VNTR loci D1S80 (pMCT 118), D17S30 (pYNZ-22 ) and ApoB3' in blood and tissues were detected by amplified fragment length polymorphism (Amp-FLP) technique,and was applied in the paternity testing cases. The discriminating power (DP) of D1S80,D17S30 and ApoB3'were 0. 962, 0. 956 and 0. 960 respectively. The cumulative probability of paternity exclusion (EPP) of the three VNTR loci was 94. 51 %,higher than that of conventional blood typings.