Genetic variation of 17 autosomal STR loci in the Lahu population from Yunnan and phylogenetic structure exploration among 28 populations

This study evaluated the genetic variation of 17 autosomal short tandem repeat (STR) loci included in the PowerPlex® 18D Kit. Samples of 562 unrelated healthy Lahu individuals living in Yunnan Province in southwestern China were investigated. The data were analyzed to provide information on allele frequencies and other statistical parameters relevant to the forensic population. Of the 17 loci, 16 reached the Hardy–Weinberg equilibrium after Bonferroni correction. A total of 176 alleles were identified in 17 STR loci, and allele frequencies ranged from 0.000 890 to 0.578 292. The combined discrimination power (CPD) and probability of excluding paternity (CPE) of the 17 STR loci were 0.999 999 999 999 999 999 489 and 0.999 998 301 753 122. The genetic relationships among 28 populations were also estimated.     

亲权鉴定判定标准可靠性的进一步确认

[目的]进一步确认我室确定的亲子鉴定判定标准的可靠性.[方法]分析本鉴定中心近几年亲子鉴定案例的结果,利用国内外群体相关基因频率资料对标准进行统计学分析并通过实践检验.[结果]利用 15个常染色体 STR位点分型作亲子鉴定时,判定被鉴定人之间是否具有亲生关系,对于双亲案,若符合孟德尔遗传规律,且亲权概率能够达到 0.999以上,则认定被鉴定人之间具有亲生关系.若检测系统中有 1个或 2个位点出现矛盾,则分别增加检测位点至 18个或 24个,没有发现新的矛盾位点时,计算父权概率,超过 0.999以上,则认定有亲生关系.只有在所检测位点中有 3个或 3个以上的 STR位点违反孟德尔遗传规律时,才可以否定被检者之间具有亲生关系.对于单亲案,在不违反孟德尔遗传规律的前提下,只能下不排除亲生关系的结论,若有 3个以上位点矛盾时,才下排除的结论.[结论]实验结果证明本中心制定和使用的判定亲权关系的标准是一个合理、可靠和实用的标准.     

New reference allelic ladders to improve allelic designation in a multiplex STR system

This paper reports the composition of a new reference allelic ladder mixture for use with a multiplex DNA profiling system consisting of six short tandem repeat loci. The loci included in this mixture are HUMTH01, D21S11, D18S51, D8S1179, HUMVWAF31/A, HUMFIBRA/FGA and an amelogenin sex test. Sequence analysis of individual ladder alleles was carried out and allelic designations made in accordance with the recommendations of the International Society of Forensic Haemogenetics (1992; 1994). A series of rare alleles which increase the range of alleles previously reported were identified. By including some of the rare alleles into the ladder marker system, we have significantly improved the ability to identify new alleles in unknown samples. Received: 12 August 1997 / Received in revised form: 7 November 1997     

Investigation of the dopamine D5 receptor gene (DRD5) in adult attention deficit hyperactivity disorder

Several lines of evidence from neuroimaging, pharmacology and genetics support the involvement of the dopaminergic system in the etiology of Attention Deficit Hyperactivity Disorder (ADHD). Previous candidate gene studies have investigated the association between a dinucleotide (CA)_n repeat polymorphism, located 18.5 kb from the start codon of the DRD5 gene, and ADHD. Association between the 148 bp allele and ADHD has been reported in some studies, however replication of the finding has not been consistent. We tested for an association between the (CA)_n repeat and adult ADHD in a sample comprised of 119 families with adult ADHD probands and 88 unrelated adult ADHD cases with a corresponding number of controls matched for age, ethnicity and sex. In the family sample we found a non-significant trend for association between the 148 bp allele and ADHD (Z = 1.91, p = 0.055). An excess of non-transmissions was detected for the 150 and 152 bp alleles (Z = −2.26, p = 0.023; Z = −2.20, p = 0.028). Quantitative analysis performed using the Brown Attention Deficit Disorder Scale (BADDS) showed association between the 150 bp allele and lower total score (p = 0.011), and lower effort (p = 0.008), activation (p = 0.008) and attention (p = 0.01) cluster scores. We did not replicate association findings in the case–control group, likely due to the lack of statistical power of this sample. Our findings add to the literature suggesting DRD5 (CA)_n repeat has a modest effect in modulating susceptibility to adult ADHD but further studies are required.     

样本量对等位基因检出数量的影响

以中国37个不同民族9个常染色体STR基因座的群体遗传研究数据资料为例，探讨群体遗传学研究中常染色体STR基因座等位基因检出数量与样本量之间的关系，即样本量对等住基因检出数量的影响。结果显示在一定范围之内，样本量的大小与所观测到的不同基因座等位基因检出数量之间存在正相关关系。当超过一定范围时，样本量的继续增加不再明显影响等位基因的检出数量。杂合度较低的位点随样本量的变化波动较大，杂合度较高的位点随样本量的变化波动较小。     

利用3个STR位点多态性研究云南19个不同民族的遗传学关系

目的选择具有高度遗传多态性与稳定性的9个STR位点,进行云南省19个不同民族的种族、民族间的遗传关系分析.方法主要进行了以下方面的研究:Hardy-Weinberg平衡吻合度检验、计算各群体间遗传距离、对各群体进行聚类分析、绘制遗传树等.结果各民族群体各位点基因型频率分布观察值与期望值符合Hardy-Weinberg平衡定律(P＞0.05).元江哈尼族与红河哈尼族、潞西阿昌族与潞西德昂族首先聚类,然后它们再次聚类;澄江回族与昆明汉族首先聚类后然后与景洪基诺族、贡山怒族聚类;罗平布依族与新平傣族、潞西景颇族与勐海布朗族,丽江傈僳族与澜沧拉祜族、澜沧佤族,红河拉祜族与剑川白族、丽江普米族各自先聚类,然后聚为一个大类;最后与贡山独龙族聚类.结论研究结果与各人群地理分布基本一致.且在对种族、民族间的遗传关系进行分析时,只有选择相同的、具有高度遗传多态性的DNA遗传标记,才可以相互比较、分析.     

CTT triplex系统各基因座位等位基因在葡萄胎基因组中的分布及其意义

我们对采用PCR和聚丙烯酰胺凝胶电泳鉴别出的37例DNA完全来自父方的遗传学完全性葡萄胎(g-CHM)进行基因组中CTTtriplex系统各基因座位(CSF1PO、TPOX和TH01)等位基因分布的分析,并初步研究了这些等位基因分布与临床预后的关系。结果显示,在37例g-CHM中,CSF1PO座位中3个等位基因(11,12和14)和TPOX座位中的1个等位基因(11)的出现率与它们在北京地区人群中的基因频率差异显著;g-CHM中CSF1PO、TPOX和TH01基因座位杂合度显著低于北京地区人群的杂合度(P值均远小于0.01);在23例良性g-CHM和10例侵袭性g-CHM中:CSF1PO座位的等位基因10、11在良性中的出现率高于在侵袭性g-CHM中(P=0.026148),等位基因12在良性中的出现率低于在侵袭性g-CHM中(P=0.023879);TPOX座位的等位基因8在良性中的出现率高于在侵袭性g-CHM中(P=0.004322),而等位基因11在良性中的出现率低于其在侵袭性g-CHM中(P=0.008671)。上述结果提示,葡萄胎基因组中存在某些等位基因分布与在人群中的分布不同,而且葡萄胎是否具有侵袭性也和某些等位基因的出现率过高或过低有相关性,这些与侵袭性有关的等位基因可能成为预测葡萄胎是否具有侵袭性的标志物。     

Carrier detection in Duchenne and Becker muscular dystrophy Argentine families

In order to offer carrier detection, genetic counseling, and prenatal diagnosis to families with Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) in our country, segregation analysis of highly polymorphic short tandem repeats (STR) (dC-dA)n: (dG-dT)n loci was utilized. The risks to females of 15 DMD/BMD families (9 familial and 6 sporadic) were evaluated on STR, pedigree and serum creatine kinase (SCK) data. From the 36 females at risk of being carriers (not including 8 obligate carriers), results of STR analysis were compatible with carrier status in 7 and not compatible in 20. In 9 females, no information regarding carriership was derived from the STR analysis. Prenatal diagnosis is now possible on the carrier females. Previously identified deletions in the central part of the gene were confirmed by STR analysis in 3 families. Five new alleles were identified in Argentine individuals; allele frequencies differed from those of North American people. Results derived from this study are useful for carrier detection and genetic counseling in DMD/BMD. One case of probable mosaicism in an unaffected father was detected on a pedigree basis in a family with DMD patients.     

Forensic characteristics and phylogenetic analysis of 23 Y-STR loci in the Miao population from Guizhou province,southwest China

Background: Investigation of haplotype/allele frequency data of Y-STR loci in ethnically diverse populations is essential for forensic reference database construction and genetic application. However, the population genetic characteristics of the Chinese Miao minority from Guizhou Province remain uncharacterised.

Aim: To assess forensic characteristics for 23 Y-Chromosomal STR loci in Guizhou Miao and explore population genetic relationships with geographically neighbouring populations.

Subjects and methods: Twenty-three Y-Chromosomal STRs were genotyped using the Powerplex^® Y23 system in 103 unrelated Chinese Miao males from Guizhou Province, southwest China. Haplotypes and forensic parameters were obtained. Population relationships of Guizhou Miao with others were revealed using AMOVA and an MDS plot.

Results: A total of 96 haplotypes were identified with overall haplotype diversity (HD) and discrimination capacity (DC) of 0.9985 and 0.9320, respectively. Genetic differentiation was observed with most of the comparison populations, prominently for Guizhou Shui.

Conclusion: The 23 Y-STR loci were highly polymorphic and discriminating in the Guizhou Miao population and could be used for forensic practice and population genetic studies. Population relationship analysis revealed Guizhou Miao had a close genetic relationship with geographically close Guizhou Gelao, as well as Han majorities derived from different regions.     

Different types of structural variation in STRs: HumFES/FPS,HumVWA and HumD21S11

Summary Alleles of the STR systems HumFES/FPS, HumVWA and HumD21S11 were sequenced and analyzed. Sequence data revealed 3 different systems concerning the complexity of their sequence structure. HumFES/FPS belongs to the STR polymorphism with a simple repeat structure. Only 2 subtypes were found with a base substitution in the 5-flanking region and no variation in the repeat region. In the STR system HumVWA the sequence structure of the repeat region is more complex, because 2 tetranucleotide units TCTA and TCTG were present. Additionally allele 14 revealed a completely different sequence structure leading to a different electrophoretic mobility. The repeat region of HumD21S11 is compound in structure. The possibility of variation at 3 positions leads to the occurrence of microheterogeneities in fragments of apparent length. In the upper allele range alleles arise with an additional incomplete TA-repeat.