ACE基因插入/缺失及β2肾上腺素受体基因多态性与房颤的相关性研究

目的：研究血管紧张素转换酶基因插入／缺失（ACEI／D）多态性及隧肾上腺素受体基因（β2-AR＋46A—G）多态性与心房颤动的相关性，寻找房颤发病的分子机制。方法：选择55例房颤患者（房颤组）及63例非房颤者（对照组），用PCR的方法检测两组ACE基因插入／缺失多态性，用RFLP法检测隧-AR＋46A→G变异。结果：房颤组与对照组ACEI／D多态性缺失纯合型（DD型）、杂合子（DI型）、插入纯合型（Ⅱ）基因型频率分别为32．76％、41．8％、25．5％和19．0％、44．4％、36．5％；房颤组与对照组β2-AR＋46A→G多态性Gly16纯合型、Arg16纯合型、Gly16／Arg16基因型频率分别是12．7％、17．47％、61．8％和14．3％、25．3％、60．3％；房颤组与对照组D等位基因、I等位基因分布频率为53．6％、46．4％和41．2％、58．7％；房颤组与对照组Gly16等位基因、Arg16等位基因分布频率为39．6％、60．4％和38．9％、61．1％；其中D等位基因分布频率在房颤组中较对照组明显增大；在9种不同基因型联合中发现，Gly／Arg型＋DD型和Gly型＋DD型的两种联合在房颤组和对照组间的分布有明显差异（P〈0．05），且这两种联合基因型发病相对危险度（OR）=2．455（95％CI：1．080～5．579）。结论：D等位基因可能是房颤的易患因素；ACEDD基因型与心肌纤维化及心脏重构的关系较为紧密，β2-AR基因＋46A→G多态性、ID基因型和Ⅱ基因型与心肌纤维化及心脏重构无明显相关性；β2-ARGly16等位基因与ACEDD基因型的联合可能对房颤的患病有着潜在的影响。     

XRCCl基因多态性与青海世居汉族乳腺癌关系的研究

目的：研究青海世居汉族人群乳腺癌易感性与x射线损伤修复交叉互补基因1（XRCC1）C26304T位点基因多态性的相关关系。方法：应用聚合酶链反应一限制性片段多态性（PCR—RFLPs）方法检测青海世居汉族人群30例乳腺癌患者（乳腺癌组）及30例乳腺良性病变患者（对照组）XRCClC26304T基因多态性分布情况。同时运用统计学方法对XRCClC26304T的基因型和基因频率进行分析。结果：XRCC1C26304T基因CC、CT、TT基因型在对照组中分别是56．7％、33．3％、10％,而在乳腺癌组中分别是50．0％、36．7％、13．3％。TT基因型在对照组及乳腺癌组中,相对于CT、CC基因组表达较低,但是对照组和乳腺癌组间并没有明显差异（P〉0．05）。经过分析,c、T基因频率在对照组中是0．733、0．267,而在乳腺癌组中是0．683、0．317,两组比较,c、T基因频率也无明显差异（P〉0．05）。结论：XRCClC26304T基因多态性可能与青海世居汉族人群乳腺癌易感性无关。     

CRELD1基因多态性与新疆维吾尔族先天性心脏病相关性研究

目的研究CRELD1基因单核苷酸多态性与新疆维吾尔族先天性心脏病的关系。方法选择112例新疆维吾尔族先天性心脏病患者和112例年龄、性别匹配的对照者。选择CRELD1基因的6个SNPs（m3894571、~3846167、m2302785、m279552、m17050660、m279551）,应用TaqManSNP基因分型的方法进行基因分型,分析CRELD1基因单核苷酸多态性与新疆维吾尔族先天性心脏病的相关性。结果患者年龄和性别在入选样本时进行了匹配,所以在分析时进行了剔除。对先心病患者母亲的年龄、文化程度、忧虑情绪、饮食状况等基本情况进行单因素分析,结果显示年龄、文化程度、忧虑情绪、饮食状况等因素与先心病发生有关联。病例组与对照组CC、CT及TT基因型频率分别为74．35％、22．28％、3．37％和83．03％、16．07％、0．90％,两组比较无统计学差异（r=5．488,P〉0．05）。两组均以CC型为主,等位基因以C占优势,病例组TT基因型频率高于对照组,但是差异无统计学意义（P〉0．05）,而CT、CT＋TT基因型频率和携带T等位基因频率高于对照组,有统计学意义（P〈0．05）。应用Logistic回归分析先心病主要相关因素：母亲年龄、文化程度、忧虑情绪、饮食状况对结果的影响,rs3894571CT、CT＋TT、CT、等位基因T因素进入回归方程。结论CRELD1基因核苷酸多态性与新疆维吾尔族先天性心脏病有相关性。     

广东省汉族人群与西藏自治区夏尔巴人群SP—A基因单核苷酸多态性研究

本文通过对肺表面活性物质相关蛋白A(SP-A)基因单核苷酸多态性(SNP)在广东汉族人群和西藏夏尔巴人群中的分布特点的分析,探讨其与高原低氧环境适应性的关系。作者应用序列特异性引物-聚合酶链反应(SSP-PCR)方法,对90名广东汉族人和104例西藏夏尔巴人SP-A基因进行检测。结果在104例夏尔巴人和90名汉族人之间SP-A1基因1544位点各基因型和等位基因分布无统计学差别(P>0.05);在SP-A1基因3241位点C/C,C/T和T/T3种基因型的构成比在夏尔巴人分别75.0%,22.1%和2.9%,而广东汉族人群为50.0%,35.6%和14.4%,夏尔巴人等位基因C、T的分布频率…     

福建地区汉族人群骨保护素基因rs2073617T/C、rs2073618G/C多态性与急性冠脉综合征的相关性研究

目的 探讨骨保护素(OPG)基因启动子rs2073617T/C(950T/C)和第1外显子rs2073618G/C(1181G/C)位点基因多态性在福建地区汉族人群中的分布及其与急性冠脉综合征(ACS)的相关性.方法 纳入福建地区无血缘关系的汉族人720例作为研究对象,分为ACS组(n=360)和对照组(n=360),采用聚合酶链式反应－限制性片段长度多态性(PCR-RFLP)技术对OPG基因950T/C和1181G/C多态性位点进行基因型分型,同时采用DNA测序对酶切产物进行鉴定.结果 在福建地区汉族人群中,OPG基因950T/C多态性TC、TT、CC 3种基因型在ACS组和对照组中的频率分别为47.8％、26.7％、25.6％和43.3％、33.3％、23.3％;1181G/C多态性GG、GC、CC 3种基因型在ACS组和对照组中的频率分别为51.1％、40.0％、8.9％和60.0％、35.0％、5.0％.ACS组与对照组OPG基因950T/C、1181G/C基因型及等位基因频率分布进行比较均差异无统计学意义(P＞0.05).OPG基因950T/C、1181G/C在ACS组患者单支病变、双支病变及三支以上病变组之间比较差异无统计学意义(P＞0.05).结论 福建地区汉族人群OPG 950T/C、1181G/C位点基因多态性与ACS发生无相关性.     

HSP70基因多态性与宁夏回汉民族2型糖尿病的关联研究

目的：探讨热休克蛋白70（heat shock protein 70,HSP70）家族基因多态性与宁夏回汉族人群2型糖尿病（ type 2 diabetes mellitus,T2DM）之间的关联。方法采用病例对照研究设计,按照纳入与排除标准,于2010年3月至2011年10月在宁夏医科大学第二附属医院与教学医院（吴忠市人民医院）收集201例T2DM患者和471例按年龄、性别、民族匹配的健康人为研究对象。应用聚合酶链反应－限制性片段长度多态性（ polymerase chain reaction-restriction fragment length polymorphism ,PCR-RFLP）技术分析基因HSP70-1（＋190G／C）、HSP70-2（＋1267A／G）和HSP70-hom（＋2437T／C）的基因型及等位基因分布的频率。采用礸2检验及Logistic回归分析研究指标与T2DM间的关系。结果 HSP70-1、HSP70-hom基因各基因型及等位基因频率在病例组及对照组的分布差异均无统计学意义（P＞0．05）,而病例组HSP70-2基因GG基因型及G等位基因频率明显高于对照组,差异均有统计学意义（礸2＝14．737,12．769,P＜0．01）;HSP70-1、HSP70-2、HSP70-hom基因各基因型及等位基因频率在回汉族人群中分布的差异均无统计学意义（ P＞0．05）;病例组与对照组中不同性别人群HSP70-1基因＋190位点和HSP70-hom基因＋2437位点基因型及等位基因频率分布的差异均无统计学意义,病例组男性HSP70-2基因型频率分布与女性比较差异无统计学意义（P＞0．05）,而等位基因频率的差异有统计学意义（礸2＝4．165,P＜0．05）;病例组男性HSP70-1、HSP70-hom基因各基因型及等位基因频率与女性比较差异均无统计学意义（P＞0．05）;多因素Logistic回归分析显示,T2DM患病的危险因素主要有腰围（waist circumference,WC）、甘油三酯（triglycerides,TG）、总胆固醇（total cho-lesterol,TC）、低密度脂蛋白胆固醇（low-density lipoprotein cholesterol,LDL-C）、收缩压（systolic blood pressure,SBP）、糖尿病家族史、G等位基因;而高密度脂蛋白胆固醇（ high-density lipoprotein cholesterol ,HDL-C）为其保护性因素。结论 HSP70-2基因GG基因型及G等位基因携带可能与T2DM的发病有关;宁夏回汉民族间HSP70家族基因各基因型及等位基因频率的分布无明显差异;糖尿病家族史、LDL-C、TC、HSP70-2 G等位基因是影响回汉族人群T2DM发病的重要危险因素;不同性别间HSP70-2基因G等位基因频率的分布可能存在差异,有待进一步研究证实。     

不同海拔汉族群体8个STR位点遗传多态性的研究

目的：研究不同海拔：青海都兰（海拔3 400m）、四川绵阳（海拔400m）汉族人群第21号染色体D21S1432、D21S1435、D21S1270、D21S1440、D21S1446、GATA24H09、ATA42C09、GATA129D11等8个STR位点的遗传多态性。方法：运用PCR扩增、6%变性聚丙烯酰胺凝胶电泳结合银染技术对不同海拔汉族人群无血缘个体进行遗传多态性研究。结果：青海世居汉族有110个基因型,频率分布在0.028 69～0.067 61之间。四川汉族有113个基因型,频率分布在0.025 99～0.067 55之间,8个STR基因座基因型分布均符合Hardy-Weinberg平衡。累积多态信息量青海为：0.685 6,四川为：0.631 8。累积杂合度为青海为：0.723 9,四川为：0.736 7。累积个体识别率（discrimination power,DP）青海为0.999 7,四川：0.996 5。结论：不同海拔汉族8个位点STR基因座的多态性数据显示有其自身的STR等位基因分布特征,两者等位基因频率比较无显著性差异（P〉0.05）。     

Nrf2基因单核苷酸多态性与急性高原病相关性研究

目的：探讨中国汉族人群中Nrf2基因多态性与急性高原病（ AMS）易感性的关系。方法采用巢式病例研究方法,以603名急进3700 m高原的中国汉族青年男性为研究对象,根据路易斯湖评分系统（ LLSS）分为病例组（n＝369）和对照组（n＝234）,采用Sequenom Mass Array 质谱阵列技术检测两组人群Nrf2基因位点rs10497511和rs2364722的基因多态性。结果病例组与对照组中rs10497511和rs2364722位点分别检测出T、C和A、G等位基因;两位点等位基因频率在两组间差异无统计学意义（P＞0．05）。进一步对2个位点的基因型共显性模型、显性模型和隐性模型分析也未提示差异有统计学意义（P＞0．05）。结论 Nrf2基因rs10497511和rs2364722位点多态性与中国汉族男性人群AMS发病可能无相关性。     

中国汉族男性军人ADRA2A基因多态性研究

目的 探讨中国汉族男性军人α2A肾上腺素能受体基因(ADRA2A)的遗传多态性及其与有氧耐力素质的关联性.方法 108名无训练史的汉族健康男性军人进行18周的有氧耐力训练,测试训练后5 000m跑的成绩.DNA测序分析ADRA2A基因的G6412C、T6623A、C6645C三个位点的多态性.分析5 000m跑成绩与基因多态性之间的关系.结果 3个多态位点的基因分布频率均符合Hardy-Weinberg平衡.ADRA2A基因6623位点杂合子A/G基因型频率为50.0%,高于纯合子G/G基因型(26.0%)和A/A基因型(24.0%);G等位基因频率为49.0%,低于A等位基因频率(51.0%).6623位点基因型为A/A的汉族男性军人5 000m测试成绩(18.97±0.65min)明显快于基因型为A/G者(20.95±0.82min),差异有显著性意义(P＜0.05),G/G基因型5 000m测试成绩(20.21±0.73min)与A/G、A/A基因型比较无显著性差异(P＞0.05).未发现G6412C、C6645C单点多态性与有氧耐力素质有明显的相关性.结论 ADRA2A基因位点T6623A多态性可作为中国汉族男性青年个体有氧耐力素质的基因标记,而G6412C和C6645C多态性不是预测个体有氧耐力素质的基因标记.     

不同年龄组人群IFABP基因外显子54A/T频率分布的研究

目的：通过分析不同年龄组人群肠脂肪酸结合蛋白（intestinal fatty acid binding protein，IFABP）基因外显子（exon）Ⅱ54位点编码丙氨酸或苏氨酸（A／T）单核苷酸多态性（single nucleotide polymorphisms，SNP）频率分布，探讨年龄变化与54A／T IFABP基因频率分布的关系。方法：将研究对象按年龄随机分为3组：14-30岁年龄组（I组，n=30），35～55岁年龄组（Ⅱ组，n=32），60～85岁年龄组（Ⅲ组，n=34）。利用聚合酶链反应（PCR）、Hha Ⅰ内切酶酶切和基因测序等技术检测各组研究对象的IFABP基因型。结果：各年龄组54A／T IFABP基因型频率分布为，Ⅰ组：A／A 60％，A／T 36．7％，T／T 3．3％；Ⅱ组：A／A 53．1％，A／T 37．5％，T／T 9．4％；Ⅲ组：A／A 29．4％，A／T 44．1％，T／T 26．5％。突变型54T基因频率分别为：22．2％（Ⅰ组），28．2％（Ⅱ组），48．5％（Ⅲ组）。与Ⅲ组比较，Ⅰ组和Ⅱ组54T型基因分布频率差别有统计学意义（分别为X^2=10．51，P＜0．01；X^2=6．19，P＜0．05）。结论：在不同年龄组，人娄IFABP基因外显子Ⅱ54A／T多态性分布存在较大差别，突变型54T随年龄的增长，出现频率升高。     

PLIN基因多态性在汉族肥胖儿童青少年中的分布及其与BMI的关系

目的:初步探讨PLIN基因多态性在中国汉族肥胖儿童青少年中的分布及其与BMI的关系。方法:通过健康体检筛选200名汉族肥胖儿童青少年,常规方法进行体格测量。利用PCR扩增及基因测序方法测定所有受试者DNA中PLIN基因多态性位点PLIN 6209T>C、PLIN 11482G>A和PLIN 14995A>T的基因型,并分析其与BMI的关系。结果:在所有受试者中,PLIN 6209T>C、PLIN11482G>A和PLIN 14995A>T多态性罕见等位基因的频率分别为0.613、0.348和0.335。PLIN6209T>C和PLIN 11482G>A强连锁不平衡(D’=0.923)。在男性受试者中,PLIN 11482G>A罕见基因的携带者(GA+AA)BMI显著高于常见基因GG的携带者(P<0.05);同时携带PLIN 6209T>C和PLIN 11482G>A罕见基因的男性受试者,即CA单倍型携带者BMI显著高于非CA携带者(P<0.05)。结论:PLIN基因多态性可能与中国肥胖儿童青少年的BMI有关,男性肥胖儿童青少年中,PLIN 11482G>A罕见基因携带者发生肥胖的风险可能高于GG基因携带者。     

中国汉族军人甘露糖结合凝集素基因多态性分析

目的：分析中国汉族人群甘露糖结合凝集素（mannose binding lectin，MBL）基因分型及单倍体分型。方法：联合应用引物序列特异性PCR扩增（PCR-SSP），序列特异性寡核苷酸探针杂交（PCR—SSOP）方法对AB，HL，PQ和XY多态性位点进行基因分型及单倍体分型，并利用该方法对212名中国汉族军人的DNA样品进行4个多态性位点的系统筛查。结果与结论：MBL基因4个多态性位点以5种单倍体型形式存在：HYPA，LYPA，LYPB，LXPA和LYQA，212份样本的单倍体型频率从高到低依次为HYPA（52．15％），LXPA（16．05％），LYPB（11．75％），LYQA（10．10％），LYPA（9．85％），共发现15种基因型，频率最高的3种为：HYPA／HYPA（27．4％），HYPA／LXPA（14．2％）和HYPA／LYPB（12．7％）。与已有研究比较，发现各民族之间的基因型频率相差较大，中国汉族人群的频率分布与亚裔人较为接近。     

Control region sequences for East Asian individuals in the Scientific Working Group on DNA Analysis Methods forensic mtDNA data set

The Scientific Working Group on DNA Analysis Methods (SWGDAM) mitochondrial DNA (mtDNA) population data set is used to infer the relative rarity of mtDNA profiles obtained from evidence samples and of profiles used to identify missing persons. In this study, the East Asian haplogroup patterns in the SWGDAM data sets were analyzed in a phylogenetic context to determine relevant single nucleotide polymorphisms (SNPs) and to describe haplogroup distributions for Asians (n = 753; with a breakdown of individuals from China n = 356, Korea n = 182, Japan n = 163, and Thailand n = 52). We focus on the patterns observed in the SWGDAM Chinese data set and refer to interesting differences in the smaller subgroup data sets for the other East Asian populations (Japanese, Korean, and Thai). A total of 218 SNPs were observed in the data set, including 37 observed positions not previously reported. In the largest of the East Asian SWGDAM data sets (Chinese), these SNPs ranged from having 1 to 29 changes in the phylogenetic tree, with site 16519 being the most variable. On average there were 4.5 changes for a character on the tree. The most variable sites (with 14 or more changes each listed from fastest to slowest) observed were 16519 (L = 29), 16311 (L = 27), 152 (L = 24), 146 (L = 21), 16172 (L = 17), 16189 (L = 17), 195 (L = 16), 16362 (L = 15), 16093 (L = 14), 16129 (L = 14) and 150 (L = 14). These rapidly changing sites are consistent with other published analyses. Only 28 SNPs are needed to identify all clusters containing 1% (n = 7) or more individuals in the East Asian data set. All 36 haplogroups previously observed in East Asian populations were also seen in the SWGDAM data sets and include: A, B, B4, B4a, B4b, B5a, B5b, C, D, D4, D4a, D4b, D5, D5a, F, F1, F1a, F1b, F1c, F2a, G2, G2a, M, M7a1, M7b, M7b1, M7b2, M7c, M8a, M9, M10, N9a, R, R9a, Y, and Z. Haplogroups A, B4a, D4, and F1a were the most commonly observed clusters in the Chinese data set (the largest of the data sets) with each of these occurring in more than 6% of the samples in the data set. The next most common haplogroups in the Chinese data set include the clusters C, M7b1, and N9a with each observed at frequencies greater than or equal to 4%. European Caucasian, and African haplogroups were rarely observed within the East Asian data sets. The various analyses revealed that the data set was similar to published East Asian data sets such as those from Han Chinese.     

Genetic data obtained for two Chinese Han populations with a quadruplex fluorescent STR typing system (HUMVWA, HUMTH01, D21S11 and HPRT)

DNA typing of four tetrameric repeat loci (HUMVWA, HUMTH01, D21S11 and HPRT) was carried out in a Chinese Han population from Shanghai (East China) and one from Guangzhou (South-East China) using a quadruplex PCR amplification and detection of the fluorescent-labeled alleles on the ALF DNA sequencer. All loci were in accordance with Hardy-Weinberg equilibrium except for D21S11 in the Guangzhou population. A test for population differentiation showed no statistical difference in the allele frequency distribution between the two populations. Comparison of the allele frequency data with other Chinese Han populations from North and South-West China for the STR loci HUMVWA and HUMTH01 revealed heterogeneity between Northern Chinese Han and Southern Chinese Han, which is in accordance with previous studies on the basis of protein markers. Received: 22 December 1997 / Accepted: 23 April 1998     

Parentally imprinted allele (PIA) typing in the differentially methylated region upstream of the human H19 gene

The H19 gene is a paternally imprinted gene located on chromosome 11p15.5. In this study, the H19FR1 and H19FR2 haplotype polymorphisms including four and three SNPs, respectively, upstream of the H19 gene according to the GenBank sequence (accession no. AF125183) were investigated. Five haplotypes and nine genotypes were detected for H19FR1 in the Chinese Han population by means of PCR and subsequent denaturing gradient gel electrophoresis (DGGE). The power of discrimination (Dp), polymorphism information content (PIC) and probability of paternity exclusion (PE) were estimated to be 0.803, 0.58 and 0.322, respectively. For the H19FR2, two haplotypes and three genotyes were observed, and the Dp, PIC and PE were 0.626, 0.37 and 0.162, respectively. Sequencing results showed that only two of the four reported SNPs, a7342g and g7547a, were detected in H19FR1 in the Chinese Han population, and two new SNPs, g7351c and a7357g, were found. In the H19FR2 region, only one of the three reported SNPs, a8097g, was detected. Based on the methylation status of the genomic DNA, selective detection of the parental alleles for H19FRs was examined by using two types of enzymes, the methylation-sensitive restriction enzyme (msRE) HpaII or HhaI and McrBC. Genomic DNA digested by either HpaII or HhaI, revealed a single band derived from the paternal allele, as a result of cleavage of unmethylated recognition sites on the maternal allele. On the contrary, the use of McrBC, which can digest a methylated paternal sequence, resulted in exclusively amplifying the maternal allele. This parentally imprinted allele (PIA) typing method could be one of the useful techniques for discriminating the parental origin of alleles.     

上海地区汉族健康人群血小板活化因子乙酰水解酶基因7号外显子593位点T/C单核苷酸多态性的研究

目的了解血小板活化因子乙酰水解酶(PAF-AH)基因7号外显子593位点T/C位点单核苷酸多态性(SNP)在中国上海地区汉族健康人群中的分布特征。方法采用聚合酶链反应(PCR)和测序法,对110名上海地区汉族健康者PAF-AH 7号外显子593位点T/C位点的SNP进行检测,计算其基因型和等位基因频率,并结合文献对不同种族该位点的突变情况进行比较。结果对110名上海地区汉族健康者PAF-AH Ile198-Thr(exon7;position 593;T-C)位点多态性进行检测,其PCR扩增产物为240bp。110人中,TT型97人(88.18%),TC型13人(11.82%),未发现CC型。该位点突变的等位基因频率分布也以T(94.09%)最为多见,其次为C(5.91%)。结合文献进行分析发现,上海地区汉族健康人群该位点突变基因型(TC)频率(11.82%)高于德国地区人群(0.95%,P<0.05),但与英国地区人群(7.67%)相比无统计学差异。结论上海地区汉族健康人群PAF-AH第7外显子593位点存在单核苷酸多态性,其T→C位点碱基突变比例较高,该位点突变基因型频率为11.82%,其SNP高于德国地区人群,但与英国地区人群相比无统计学差异。     

C1GALT1基因变异与IgA肾病遗传易感性的相关性研究

目的 通过病例对照关联研究,研究分析C1GALT1和C1GALT1C1基因的单核苷酸多态性（single nucleotide polymorphisms,SNPs）与新疆地区维吾尔族人群IgA肾病（IgA nephropathy,IgAN）易感性之间的关联。方法 共选取1 014名受试者,其中包括595名IgAN患者和419名地理和民族匹配的健康对照者。选择C1GALT1中的 734C/T,-465A/G,-330G/T,-292C/-和1365G/A 5个SNPs作为标记SNP。结果 IgAN患者-292C/-的D等位基因和DD基因型显著低于对照组（P<0.01）。IgAN患者的单倍型YATIG（Y=C或T）频率显著低于对照组（0.0726 vs 0.1202,P=2.684×10-4,OR=0.68）。IgAN患者的单倍型YAGDA（0.1187 vs 0.0684,P=3.671×10-3,OR=1.72）和YATDG（0.0827 vs 0.0275,P=1.197×10-5,OR=2.87）显著高于对照组。结论 C1GALT1基因的变异与新疆地区维吾尔族IgAN遗传易感性相关。     

An investigation of a set of DIP-STR markers to detect unbalanced DNA mixtures among the southwest Chinese Han population

The resolution of DNA mixtures is still a difficult problem that is worthy of further study. A common method applied for analysing mixtures is the use of autosomal STR markers as well as related calculation software based on genotypes; however, these markers have a limitation in detecting minor DNA in unbalanced mixtures if major DNA constitutes over 95% of the stain. Novel biomarkers, such as Y-STR, DIP-STR and SNP-STR, have been shown to perform well in distinguishing DNA donors in this type of mixture. DIP-STR can successfully target minor DNA in 1000-fold background DNA using two separate allele-specific primers. However, whether this method can successfully detect minor DNA primarily depends on the distribution of the DIPs in a population. Until now, only Swiss population data have been reported; therefore in this study, we selected 10 DIP-STR markers that performed well in the Swiss population and investigated whether these markers were also useful among the southwest Chinese Han population. The allele frequencies were estimated based on 152 samples, and six of the ten DIP-STR makers had a relatively high probability of informative markers (I value), which indicated their potential usefulness in the southwest Chinese Han population. A comparative study of DIP-STR markers and autosomal STR markers demonstrated that DIP-STR markers detected minor DNA at a ratio of 1:1000, while autosomal STR markers often failed to genotype minor DNA because of strong background noises caused by large amount of major DNA. However, the discrimination power was not high enough using these six DIPs alone. Therefore, we suggest that development of a panel with more loci is imperative and that a panel combined with DIP-STR and SNP-STR markers may be a possible way to achieve better discrimination power.     

Variants of the melanocortin 1 receptor gene (<Emphasis Type="Italic">MC1R</Emphasis>) and <Emphasis Type="Italic">P</Emphasis> gene as indicators of the population origin of an individual

The population origin of an individual is often requested to be determined from specimens left at a crime scene for identifying a suspect and individual identity. The melanocortin 1 receptor gene (MC1R) and P gene are associated with human pigmentation. Although several studies have reported that these genes are highly polymorphic in human populations, it is unclear if the allele variants can be used to determine the population origin of an individual. We aimed to determine the ethnic origin of an individual by using single nucleotide polymorphisms (SNPs). Eighteen SNPs in the MC1R gene and P genes were genotyped in 52 individuals by the direct sequencing method, and 4 SNPs (MC1R gene: R163Q and P gene: IVS5 + 1001, IVS13 + 113, and H615R) were selected on the basis of differences in frequencies. Subsequently, we genotyped these four SNPs in 422 volunteers from six ethnically defined populations using a polymerase chain reaction-based assay. The results revealed that the allele variants were present with high frequencies in Asian populations but were low in European and African populations. On the basis of these results, we defined a specific combination of a genotype (R163Q) and a diplotype group (IVS5 + 1001, IVS13 + 113, and H615R). This study indicates that the specific combination of a genotype and a diplotype group would be effective in estimating the population origin of an individual from a list of population groups. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Fifteen non-CODIS autosomal short tandem repeat loci multiplex data from nine population groups living in Taiwan

The analysis of autosomal short tandem repeat (STR) loci is a powerful tool in forensic genetics. We developed a multiplex system in which 15 non-Combined DNA Index System autosomal STRs (D3S1744, D4S2366, D8S1110, D10S2325, D12S1090, D13S765, D14S608, Penta E, D17S1294, D18S536, D18S1270, D20S470, D21S1437, Penta D, and D22S683) could be amplified in one single polymerase chain reaction. DNA samples from 1,098 unrelated subjects of nine population groups living in Taiwan, including Taiwanese Han, indigenous Taiwanese of Taiwan Island, Tao, mainland Chinese, Filipinos, Thais, Vietnamese, Indonesians, and Caucasians, were collected and analyzed using this system. The distributions of the allelic frequencies and the forensic parameters of each population group were presented. The combined discrimination power and the combined power of exclusion were high in all population groups tested in this study. A multidimensional scaling plot of these nine population groups based on the Reynolds' genetic distances calculated from 15 autosomal STRs was constructed, and the genetic substructure in this area was presented. In conclusion, this 15 autosomal STR multiplex system provides highly informative STR data and appears useful in forensic casework and parentage testing in different populations.