双亲皆疑亲子鉴定STR分型亲权指数计算方法探讨

计算标准三联体亲子鉴定的PI值及探讨双亲皆疑亲子鉴定PI值计算的可靠方法 ,对常规STR分型鉴定结果 ,根据Eseen M ller计算理论 ,总结出标准三联体亲子鉴定计算PI值的 4个公式 :1/ p ,1/ ( 2 p) ,1/ (p +q) ,1/ ( 2p +2 q)。提出适用于双亲皆疑亲子鉴定的一种新的PI值计算方法 ,并与其他方法进行比较。认为该方法取值Y时 ,既考虑随机男女生孩子的可能性 ,也考虑假设父 (或假设母 )与随机个体生孩子的可能性 ,更符合随机原则。     

亲权鉴定若干问题综述

对亲权鉴定中遗传标记的研究历史及现状进行了综述，并对国际法医遗传学会亲子鉴定委员会关于DNA生物计算的建议进行了解读。     

单亲亲子鉴定的分析研究

目的从理论和实际应用方面客观评价13～15个STR位点应用于单亲亲子鉴定的准确性。方法依据中国人群基因频率资料,计算单亲亲子鉴定的非父排除率及单亲亲子鉴定的亲子关系概率,并选择有明确排除结论的104例排除案例,分析统计其中父-子二联体出现的排除指标数。结果对于单亲亲子鉴定,选用13～15个STR位点,联合非父排除率为0.9805～0.9906;亲子关系概率均大于99.73%。104例二联体排除案例中,有3例的排除指标数小于2,未发现排除指标为零的现象。结论若应用ProfilerPlus和CofilerPlus试剂盒的13个STR位点进行日常单亲亲子鉴定工作,存在微弱漏判非父的风险,必要时增加检测指标数。不排除案例的单亲亲子鉴定,其亲子概率均可达国际认定标准。     

Chromosome heteromorphisms and paternity testing

Most of the blood group systems have now been applied to paternity investigations. In a complicated case, an alleged father not excluded with blood group testing, could be excluded with only chromosome heteromorphisms. Chromosome heteromorphisms are inherited from parents to offspring as simple Mendelian laws. The authors' paternity testing is presented with the help of chromosome heteromorphism analysis.     

Unusual association of three rare alleles and a mismatch in a case of paternity testing

This study reports a paternity case analyzed by the AmpFlSTR Identifiler Kit (AB) in which father and daughter shared three rare alleles for D19S433, D18S51 and TH01 microsatellites. The case also showed an apparent exclusion, due to a mutation at the D3S 1358 microsatellite. Sequencing analysis was performed to assess the size of the rare alleles and to establish their structure, which revealed some molecular variations in regions flanking the motif repeats.     

ISFG: Recommendations on biostatistics in paternity testing

The Paternity Testing Commission (PTC) of the International Society for Forensic Genetics has taken up the task of establishing the biostatistical recommendations in accordance with the ISO 17025 standards and a previous set of ISFG recommendations specific to the genetic investigations in paternity cases. In the initial set, the PTC recommended that biostatistical evaluations of paternity are based on a likelihood ratio principle – yielding the paternity index, PI. Here, we have made five supplementary biostatistical recommendations. The first recommendation clarifies and defines basic concepts of genetic hypotheses and calculation concerns needed to produce valid PIs. The second and third recommendations address issues associated with population genetics (allele probabilities, Y-chromosome markers, mtDNA, and population substructuring) and special circumstances (deficiency/reconstruction and immigration cases), respectively. The fourth recommendation considers strategies regarding genetic evidence against paternity. The fifth recommendation covers necessary documentation, reporting details and assumptions underlying calculations. The PTC strongly suggests that these recommendations should be adopted by all laboratories involved in paternity testing as the basis for their biostatistical analysis.     

A case of paternity testing influenced by the silent allele of Rh erythrocyte groups

A paternity test is presented in which a father and his two children possessed an extremely rare amorphic gene R-29 (r,---). One of the children was determined to be illegitimate at the first trial as her Rh phenotype was R2R2(ccDEE) and the father's phenotype was R1R1(CCDee). At the Court of Appeal, however, the rare Rh gene r(---) was shown to be inherited from the father to the appellant child through extended tests including her brother whose phenotype was also R2R2(ccDEE). She was acknowledged to be legitimate.     

PowerPlex~(TM) 16体系在亲子鉴定中的应用评估

目的 评估PowerPlexTM16体系在亲子鉴定中的检验能力。方法 以633例亲子鉴定案例为基础,调查PowerPlexTM16体系15个STR基因座的群体遗传学数据资料,并对该体系在亲子鉴定中的排除能力及遗传稳定性进行评估。结果 879名无关个体共检出197个等位基因,739种基因型,累计个体识别力为1×10-30,累计非父排除率为0.999999999999987。633例亲子鉴定案件中有95例确定为排除亲权,平均排除指标为6个。18例表现出1个STR基因座突变的现象,1例表现出2个STR基因座突变的现象。结论 PowerPlexTM16体系应用于亲子鉴定是高效、可靠的。     

Simultaneous phenotyping of genetic markers for paternity testing

Time-and cost-saving methods for paternity testing are described. Seventeen genetic systems were divided into six groups: (1) transferrin (Tf), factor B (Bf), and phosphoglucomutase 1 (PGM1); (2) group-specific component (Gc) or alpha 1-antitrypsin (PI) and alpha 2HS-glycoprotein (HSGA); (3) complement components C6 and C7, factor 13B (F13B), and plasminogen (PLG); (4) haptoglobin (Hp), C8 alpha-gamma chain (C81), and factor I (IF); (5) red cell acid phosphatase (ACP), esterase D (ESD), and glutamic-pyruvic transaminase (GPT); and (6) 6-phosphogluconate dehydrogenase (PGD) and glyoxalase I (GLO). Each group of systems was typed simultaneously by electrophoresis or isoelectric focusing (IEF) followed by staining or immunoblotting. These methods are very practical because they afford a considerable saving of time, work and expense, and facilitate semipermanent preservation of electrophoretic patterns.     

HLA-A基因座多态性在亲子鉴定中的应用研究

首次将HLA A基因座的聚合酶链反应 寡核苷酸探针 (PCR SSOP)杂交分型技术应用于亲子鉴定案例分析 ,以获得HLA A基因座多态性用于法医学鉴定分析的基础数据。HLA A基因座基因分型的等位基因检出率 ( 2 4个 )和非父排除率 ( 73 3 % )均高于血清学检测方法 ;正常家系分析结果符合孟德尔遗传规律。对 3 9个亲子鉴定例的成员进行HLA A基因检测 ,9例排除 ( 2 3 1% ) ;未排除的 3 0例的亲子关系概率在 65 2 %～ 99 5 %之间。用PCR SSOP技术对HLA基因座基因分型不仅可以应用于亲子鉴定和法医学个人识别 ,还可以应用于器官移植配型及人类遗传学研究。     

Prenatal and newborn paternity testing with DNA analysis

In rape against youthful girls which yields pregnancy after the abortion DNA examinations can be performed from the aborted foetal material to provide evidence of paternity of the suspect. In our present work we demonstrate six cases: four of them are rape cases and two where the mother abandoned her newborn baby. These cases proved that DNA-STR profiles can be determined from foetus after the abortion and perpetrator of a rape can be found. Due to our result we suggest that not only placenta but also bloody vernix caseosa is useful tissue for identifying the putative mother because vernix caseosa can be the carrier of the mother's blood.     

Probability of exclusion in paternity testing: time to reassess

The average exclusion probability is a measure of efficiency in paternity testing; it refers to the a priori ability of a battery of tests to detect paternity inconsistencies. This parameter measures the capacity of the system to detect a false accusation of paternity. Traditionally, this average exclusion probability has been estimated as the probability of excluding a man who is not the father by an inconsistency in at least one of the studied loci. We suggest that this criterion should be corrected, as currently the presumed father is excluded when at least three genetic inconsistencies are found with the child being tested, not just one. This change of criterion has occurred because of the use of microsatellite loci, whose mutation rates are much greater than those of the coding genes used previously in paternity studies. We propose the use of the average probability of exclusion for at least three loci (not only one), as an honest measure of the combined probability of exclusion of several loci, and we propose an algebraic expression to calculate it.     

亲子鉴定中STR基因座的基因突变分析

目的探讨Identifiler^TM荧光标记复合扩增试剂盒15个STR基因座在亲子鉴定中的基因突变特点。方法应用Identifiler^TM荧光标记复合扩增试剂盒检测676例亲子鉴定案，对其中1～2个突变基因座加做HLA等位基因检测或Y—STR基因座检测。结果在认定亲子关系的676例中，观察1304次减数分裂，Identifiler^TM荧光标记复合扩增试剂盒中的15个基因座确定19例突变，其中D18S51基因座4例，D2S1338基因座3例，D8S1179、D16S539、vWA、D7S820、D13S317基因座各2例，D5S818和TH01基因座各1例，D21S11、FGA、D3S1358、D19S433、TPOX、CSF1P0基因座未见突变；一步突变的17例，二步突变的为1例，四步突变的1例；1个基因座发生突变的18例，2个基因座同时发生基因突变的为1例；突变来自父亲与来自母亲的比例为13：2，4例来源不能确定。结论用Identifiler^TM荧光标记复合扩增试剂盒检测到1—2个基因座发生突变，须增加对其它遗传标记的检测。     

Identifiler体系在单亲血缘关系鉴定中应用价值的研究

目的研究16基因位点Identifiler体系在单亲血缘关系法医鉴定中的应用价值. 方法对无关个体中随机抽样组成的假设父-子二联体100例、正常人群中已知真父-子二联体100例及已知非父-子二联体100例、实际单亲血缘关系亲子鉴定案228例、特意省去母亲的二联体鉴定案136例,应用Identifiler体系的16基因位点进行检测,得出每案例的RCP值,将检测结果同应用其他体系检测的结果比对,同三联体检测结果比对,同真实情况比对,计算出单独使用Identifiler体系在单亲血缘关系法医鉴定中的正确率. 结果对228例单亲鉴定案应用Identifiler体系检测的结果,同应用Profiler Plus和Cofiler两个体系再加用24个其他位点银染检测(共37个位点)的结果完全相同;对无关个体100例及真父-子二联体100例及非父-子二联体100例,用Identifil er体系检测的结果同调查核实的真实情况完全相符;对136例特意省去母亲的二联体案,用I dentifiler体系检测的结果同原实际检案中三联体检测的结果完全相同. 结论 单独使用Identifiler体系完全可以解决法医亲子鉴定中的单亲血缘关系鉴定问题.     

The expected performance of single nucleotide polymorphism loci in paternity testing

We discuss the utility of single nucleotide polymorphism loci for full trio and mother-unavailable paternity testing cases, in the presence of population substructure and relatedness of putative and actual fathers. We focus primarily on the expected number of loci required to gain specified probabilities of mismatches, and report the expected proportion of paternity indices greater than three threshold values for these loci.     

User-friendly programs for easy calculations in paternity testing and kinship determinations

Four computer programs are developed for easy calculations of likelihood ratios (LRs) for paternity testing and kinship determinations. The programs are constructed based on the concepts of Bayes Theorem, conditional probability and pedigree analysis. Computer enumeration is used for handling the calculations. The programs have wide applicability, and users can save and check the results easily. The programs employ the distinctive pull-down manual, making them very easy to use. In this paper, we explain the theory and describe various features of the software.