山西汉族X-STR基因座DXS9902、DXS7132的遗传多态性

X染色体STR基因座由于其独特的遗传方式,在法医学鉴定的一些特殊案件中表现出了常染色体遗传标记无法比拟的优势,已有多个X染色体的STR基因座被应用于法医学鉴定。本研究通过对山西汉族人群DXS9902和DXS7132两个X-STR基因座及单倍型遗传多态性进行调查,为法医学个体识别、亲子鉴定及遗传学研究等提供了基础数据。     

潍坊汉族男性27个X-STR基因座遗传多态性

位于X染色体的STR由于其独特的遗传方式,在法医学领域有其独特的应用价值,已引起了法医工作者的关注。本研究应用荧光标记、复合扩增技术对潍坊汉族男性群体X染色体上的27个STR基因座的遗传多态性进行了研究,获得了相关的遗传多态性数据,为进一步的法医学和群体遗传学应用研究奠定了基础。     

HLA基因多态性及其法医学应用

人类白细胞抗原(Human Leukocyte Antigen,HLA)基因复合物定位于人类第6号染色体短臂上,是人类最复杂的显性多态遗传系统,基因型可达108种之多,是理想的人类遗传标记,已广泛应用于法医学亲子鉴定和个体识别。本文就其基因多态性的研究进展和在法医学中的应用作一综述。     

山西汉族群体DXS6804和DXS6800遗传多态性

X染色体STR在一些缺失亲代的姐妹亲权鉴定案件中具有一些常染色体遗传标记所没有的优点。本文报道DXS6804和DXS6800两个X-STR基因座的遗传多态性,旨在为法医学应用提供基本数据。     

湖南地区汉族人群12个常染色体STR基因座的遗传多态性

STR基因座因其在人类基因中分布广泛、片段小、易扩增，所需检材微量及其高度杂合性、高度多态性而广泛应用于构建人类遗传图谱、基因定位、遗传病连锁分析、基因诊断和法医学鉴定方面。本研究探讨了湖南汉族人群12个常染色体STR基因座的遗传多态性，为该地区汉族人群法医学个人识别和亲权鉴定提供基础数据。     

X染色体遗传标记研究进展

随着人类基因组计划的进展,全面深入地了解个体和群体间基因组的变异或多态性已成为可能,并日益显示其重要性。X染色体遗传标记的遗传多态性较多地表现在短串联重复序列和单核苷酸的多态性。这类多态性有助于解释个体的表型差异、不同群体和个体对疾病,特别是对复杂疾病的易感性、以及对各种药物的耐受性和对环境因子的反应,因此受到临床及法医工作者的重视。本文收集了国内外X染色体遗传标记在临床疾病诊断及法医DNA工作者实践中的研究和应用资料,汇总报道了X染色体遗传标记的研究进展。     

新疆汉族和维吾尔族群体5个X-STR基因座的遗传多态性

近年来X染色体STR(X-STR)已得到法医工作者的青睐,与常染色体STR联合应用于法医学实践[1-5].X-STR与常染色体STR相比有其独特的特征[6],遗传过程中母亲的X染色体可以遗传给女儿和儿子,而父亲的X染色体只能遗传给女儿.由于单个X-STR提供的信息有限,因此有必要寻找更多多态性高的X-STR基因座并建立群体遗传学资料[7-8].本研究应用二色荧光标记5个X-STR基因座(DXS6803、DXS981、DXS6809、DXS6789和DXS7132)复合扩增体系,调查新疆汉族和维吾尔族群体多态性,比较其差异,获得2个群体的遗传学数据.为建立X-STR基因座群体遗传学资料和建立X-STR数据库奠定基础.     

Y－染色体SNPs及其在法医学中的应用价值

随着人类基因组计划的迅猛发展,已有越来越多的Y染色体SNP位点被发现,在个人识别、家系谱的建立、疾病的预测与诊断方面,Y染色体单核苷酸多态性提供了非常有价值的遗传标记。同样在法医学中也有广阔的应用前景。本文综合介绍了SNP和Y-SNP的一般特性及在法医学中的应用价值。     

新疆维吾尔族群体16个Y-STR基因座遗传多态性

正常男性具有Y染色体并遵循父系伴性遗传规律,Y-STR遗传标记在法医学个体识别鉴定中有独特的应用价值。本文对新疆维吾尔族群体288名无关男性个体16个Y-STR基因座遗传多态性进行调查,为该群体的法医学实践提供基础数据。     

X染色体上高信息量SNP位点及其法医学价值

人类X染色体长154.8Mb,其上密布SNP位点,蕴涵着大量的信息。用于法医学鉴定的X-SNP标记多态性好、突变率低。本研究从Hapmap、NCBI的数据库中筛选了167个高信息量SNP位点,这些位点的等位基因在北京汉族人群中的分布频率均高于0.3,通过高通量、高灵敏度的检测方法可对各个X-SNP位点进行分型验证,通过正确的统计学分析可得到其法医学多态性参数。X-SNP位点具有一些常染色体遗传标记无法比拟的优点,作为常规STR基因座的补充,能用于解决特殊的亲子鉴定案,性别鉴定和混合斑鉴定。     

新一代遗传标记——InDel研究进展

法医DNA分型经历了三代遗传标记的研究,短串联重复序列(short tandem repeat,STR)作为比较成熟的工具已被广泛运用于法医生物学鉴定中。进一步对人类基因组的探索,先后发现了单核苷酸多态性(single nucleotide polymorphism,SNP)、插入/缺失(Insertion/Deletion,InDel)等一系列遗传标记,而其中InDel作为新型的遗传标记,基本兼具各类遗传标记的优点,受到包括医学分子生物学和法医生物学在内各领域的广泛关注。本文就InDel的研究历史与相应的成果进行简单总结与回顾,以时间轴与研究目的为主要的分类指标,重点关注以多个InDel联合作为遗传标记的多重扩增系统(常染色体或X染色体)在法医生物学及人类学研究中的进展,并对今后该领域研究的方向与暨待解决的问题进行了综述。     

二代测序技术在Y染色体遗传标记分型中的法医学应用

法医遗传学领域常利用Y染色体的父系遗传特点,对非重组区遗传标记进行检测并用于亲缘关系鉴定、混合斑检测、家系排查以及种族推断等研究.目前毛细管电泳仍是应用最为广泛的检测技术,基于该技术的商业化检测试剂盒及数据分析处理系统十分成熟.随着生物信息量的增长,传统检测技术通量低的弊端逐渐显现,推动了法医DNA分型技术的革新.近年...     

Paternal half-sisters or unrelated – How can the X-chromosomal evidence be quantified when one female presents trisomy X?

The X chromosome has unique features, such as haplodiploid mode of genetic transmission, which can be crucial to complement autosomal profiling or to disentangle complex kinship problems. Indeed, for some cases (e.g. full- or paternal half-sisters, or paternal grandmother-granddaughter hypotheses), X-markers are expected to provide a similar or a higher power to the one obtained with autosomes in paternity/maternity investigations. Both theoretical and informatics frameworks for pairwise X-linked kinship analyses are well established for individuals with a regular number of chromosomes, but these are still lacking for individuals exhibiting an X chromosome aneuploidy, such as females with Triple X (47, XXX) syndrome. Indeed, this work was motivated by a real forensic case involving the evaluation with X-chromosomal markers of the hypotheses that two women were related either as paternal half-sisters or as unrelated, one of them showing a trisomy X. In this case, the analysis of X-chromosomal markers would yield stronger results than autosomes, as females had to share at least one identical allele in each analyzed X chromosome marker under the paternal half-sibling hypothesis, unless a mutation occurs. To fulfill this gap, we present in this work algebraic formulae for some genotypic configurations, which will allow quantification of the evidence on the referred cases. A general approach, comprising other X chromosome aneuploidies, kinship hypotheses, and genotypic configurations, is currently being developed by us. This work is the starting point to analyze X-chromosomal data under the scope of kinship problems, involving individuals with aneuploidies. This will improve the quantification of DNA evidence not only in forensic casework, but also in the field of medical genetics, whenever individuals with X-chromosomal aneuploidies are involved.     

Updated allelic structures of the DXS10135 and DXS10078 STR loci

DXS10135 and DXS10078 are two highly polymorphic STR loci situated in two different linkage groups on the short arm of the human X chromosome. Both loci comprise complex tetrameric repeat units which may partially explain their high degree of polymorphism. DXS10135 is relatively well characterized and is included in a commercially available kit, while DXS10078 has not been well described. We sequenced a large number of alleles of both loci to try and understand the allelic variation and as a prelude to construct allelic ladders from cloned alleles. Our data show interesting features and should encourage other workers to use these loci in forensic genetic investigations.     

Assessing the potential application of X-chromosomal haploblocks in population genetics and forensic studies

Haploblocks are segments of the genome with little recombination that may be of interest in forensic and population genetics. Criteria to select autosomal haploblocks have been previously described, leading to the identification of candidate regions that, a priori, met the conditions to be used as forensic genetic markers. Still, the potential of X-chromosomal haploblocks remains unexplored.The present work aimed to provide basis for designing strategies for selection of X-haploblocks defined by single nucleotide polymorphisms (SNPs) using next generation sequencing approach. The potential application in population genetics and forensic studies was addressed. One of the conditions considered in the haploblock selection was the simultaneous inclusion of short tandem repeats (STRs) currently used in forensic casework to allow the distinction between SNP-defined haplotypes and increase the resolution for fine-scale studies. Given the size of the X chromosome (∼150 Mbps), only four haploblocks could be selected in order to guarantee their independence.     

Development of a heptaplex PCR system to analyse X-chromosome STR loci from five Italian population samples. A collaborative study

Many X-chromosome short tandem repeats (X-STRs) have been validated for forensic use even if further studies are needed on allele frequencies and mutation rates to evaluate the extent of polymorphism in different populations and to establish reference databases useful for forensic applications and for anthropological studies. A single multiplex reaction of seven X-STRs, which includes the DXS6789, HUMARA, DXS10011, DXS7423, HPRTB, DXS6807, DXS101 loci, is presented and their allele frequency distribution in a large population sample including 556 subjects (268 females and 288 males) analysed by five forensic laboratories of Central and Northern Italy is shown. Our results demonstrate the feasibility of a single amplification/detection reaction involving seven markers of the X chromosome, which can be fruitfully used in complex kinship analysis.     

Human Leukocyte Antigen alleles as an aid to STR in complex forensic DNA samples

Human biological samples with multiple contributors remain one of the most challenging aspects of DNA typing within a forensic science context. With the increasing sensitivity of commercially available kits allowing detection of low template DNA, complex mixtures are now a standard component of forensic DNA evidence. Over the years, various methods and techniques have been developed to try to resolve the issue of mixed profiles. However, forensic DNA analysis has relied on the same markers to generate DNA profiles for the past 30 years causing considerable challenges in the deconvolution of complex mixed samples. The future of resolving complicated DNA mixtures may rely on utilising markers that have been previously applied to gene typing of non-forensic relevance. With Massively Parallel Sequencing (MPS), techniques becoming more popular and accessible even epigenetic markers have become a source of interest for forensic scientists.The aim of this review is to consider the potential of alleles from the Human Leukocyte Antigen (HLA) complex as effective forensic markers. While Massively Parallel Sequencing of HLA is routinely used in clinical laboratories in fields such as transplantation, pharmacology or population studies, there have not been any studies testing its suitability for forensic casework samples.     

X—STR基因座的法医学应用研究进展

对X染色体的结构特征、遗传特征及其短串联重复序列（STR）基因座在法医学领域的研究历史、现状进行了综述。并分析了X染色体STR基因座在混合斑鉴定和复杂亲子关系鉴定中的应用,以及在法医学领域应用中应注意的问题．如单倍型和连锁不平衡现象等。