The evolution and formation of RH genes

The Rh system clinically is one of the important blood groups. The major Rh antigens, which are constituted by over 40 types, are RhD, RhC/c, and RhE/e. Furthermore, Rh blood group system is characterized by the existence of many variants.It was considered that Rh blood group system was encoded on two genes termed the RHCE and RHD, which are composed of ten exons, respectively. It is inferred that the RHD gene encodes the RhD antigen and that the RHCE gene encodes the Rh C/c and RhE/e antigens. There are RHce, RHCe, RHcE and RHCE alleles as polymorphisms of RHCE gene. In 2000, the entire nucleotide sequences in all introns of both the RHD and RHCE genes were determined. Due to the new findings on RH genes, it is thought that multiple recombination (and/or gene conversion), nucleotide substitutions, small nucleotide gaps, replication slippage of microsatellite, large nucleotide gaps (due to Alu sequence) and the high level of the homology (%) between both RH genes are the important factors in the formation and evolution of both RH genes and Rh variants. Based on the advance of human genome project, the new interpretations on the evolution and formation of RH genes and Rh variants will be performed.Human Rh family (superfamily) and its counterparts in primates, mammals, fish, amphibians, bacteria, lower eukaryotes, archaea and plants have been identified. A lot of findings have been accumulated in their evolution and function. As gene conversions or recombination events confuse the phylogenetic tree of human RH genes and their counterparts, careful attention is necessary for researchers to calculate the time of gene duplication and to discuss the evolution of Rh family and its counterparts.Rh genotyping methods will never be perfect and both the clinicians and researchers have to recognize the limitation of Rh genotyping, especially RhD genotyping, because new Rh variants must have formed continually. In applying the Rh genotyping to clinical medicine, especially transfusion medicine, it is necessary to compare and examine the serological (phenotypic) data in Rh blood group system with caution.     

RHC/c genotyping based on polymorphism in the promoter region of the RHCE gene

Designing of PCR tests for the RHC allele is difficult because of the high DNA sequence homology between RHC and RHD genes, which differ by only a one-nucleotide substitution at position 48 in exon 1 of the RHCE gene. We sequenced the promoter region of the RHCE gene, and compared our results with the reported sequence. Genomic DNA was prepared from blood samples collected from 656 Japanese donors. The DNA segment encompassing the promoter region and exon 1 of the RHCE gene from 30 donors was amplified by PCR and analyzed by DNA sequencing. Four nucleotide differences between RHC/c and RHD were found at positions -468, -304, -58, and -46. On the basis of the nucleotide differences at positions -468 (RHCE vs. RHD) and -292 (RHC vs. RHc), we then developed a novel polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method for RHC/c genotyping. Analysis of the genomic DNA from the 656 donors revealed that this method could discriminate RHC from RHc, irrespective of the RHD genotype, with only a few exceptions. The combination of our system and the intron 2-based PCR-RFLP method previously reported may prove to be more accurate than either of the methods alone, and therefore, useful and valuable for RHC/c genotyping.     

Coronal 2D MR cholangiography overestimates the length of the right hepatic duct in liver transplantation donors

Purpose

To compare the length of the right hepatic duct (RHD) measured on rotatory coronal 2D MR cholangiography (MRC), rotatory axial 2D MRC, and reconstructed 3D MRC.

Materials and methods

Sixty-seven donors underwent coronal and axial 2D projection MRC and 3D MRC. RHD length was measured and categorized as ultrashort (≤1 mm), short (>1-14 mm), and long (>14 mm). The measured length, frequency of overestimation, and the degree of underestimation between two 2D MRC sets were compared to 3D MRC.

Results

The length of the RHD from 3D MRC, coronal 2D MRC, and axial 2D MRC showed significant difference (p?<?0.05). RHD was frequently overestimated on the coronal than on axial 2D MRC (61.2 % vs. 9 %; p?<?.0001). On coronal 2D MRC, four (6 %) with short RHD and one (1.5 %) with ultrashort RHD were over-categorized as long RHD. On axial 2D MRC, overestimation was mostly <1 mm (83.3 %), none exceeding 3 mm or over-categorized. The degree of underestimation between the two projection planes was comparable.

Conclusion

Coronal 2D MRC overestimates the RHD in liver donors. We suggest adding axial 2D MRC to conventional coronal 2D MRC in the preoperative workup protocol for living liver donors to avoid unexpected confrontation with multiple ductal openings when harvesting the graft.

Key Points

? In living liver donors, RHD length influences the number of ductal openings. ? Coronal 2D MRC overestimates the RHD length than does axial 2D MRC. ? Adding axial 2D MRC to coronal 2D MRC may prevent overestimating RHD length.

     

抗Rh（D）抗体制备的研究进展

RhD抗原是表达在人类红细胞表面的血型抗原,其在免疫原性和临床上的应用仅次于ABO血型系统,相应的抗Rh（D）抗体在血型鉴定和预防新生儿溶血等方面均具有重要意义。传统的抗Rh（D）多克隆抗体来自健康人的血清,由于来源受限和血浆制品的安全问题,人们开始了抗Rh（D）的单克隆抗体和基因工程抗体的研究。国外研制的抗Rh（D）的单克隆抗体已成功用于血型鉴定,但到目前为止,还没有一个单克隆或者基因工程抗Rh（D）抗体作为多克隆抗Rh（D）抗体的替代品,在临床上用于预防Rh（D）免疫和新生儿溶血。本文对抗Rh（D）抗体制备的研究进展进行了综述。     

11 169例孕产妇不规则抗体筛查结果分析

目的 通过分析孕产妇不规则抗体产生的频率与特异性,探讨不规则抗体筛查在孕产妇整个妊娠周期的临床意义。方法 采用微柱凝胶法对2010年1月-2020年12月在解放军总医院第六医学中心输血医学科生产备血的孕产妇做不规则抗体筛查,对抗体筛查结果阳性的做进一步抗体特异性鉴定。结果 11 169例抗体筛查结果中52例为阳性（0.47%）,其中Rh血型系统26例（50.0%）;MNS血型系统9例（17.3%）;Lewis血型系统5例（9.6%）;kidd血型系统1例（1.9%）;3例（5.8%）抗体水平较弱,未检出特异性;1例（1.9%）温自身抗体;7例（13.5%）患者拒绝检测。A型Rh阳性15例;B型Rh阳性9例;O型Rh阳性11例;AB型Rh阳性4例;A型Rh阴性4例;B型Rh阴性5例;O型Rh阴性2例;AB型Rh阴性2例。结论 孕产妇抗体筛查阳性不仅会造成交叉配血困难,给安全输血带来难度,而且会造成妊娠生产不良反应,严重的会发生新生儿溶血病。整个妊娠周期的不规则抗体筛查是保障孕产妇安全生产,早预防、早治疗新生儿溶血病,以及孕产妇安全输血的前提,具有重要的临床意义。     

慢性阻塞性肺疾病免疫学指标的变化及其与DNA短串联重复序列的关联

目的探讨慢性阻塞性肺疾病(COPD)患者血液免疫学指标与DNA短串联重复序列的关联性。方法选取COPD患者40例及健康对照组100例应用全自动生化分析仪测定血液IgA、IgG、IgM、C3、C4,并应用第二代DNA遗传标记-短串联重复序列(STR)对D8S1179、D21S11、D7S820、CSF1P0、D3S1358、D5S818、D13S317、D16S539、D2S1338、D19S433、VWA、D12S391、D18S51、D6S1043、FGA 15个STR基因位点的遗传多态性进行分析。结果 COPD组免疫学指标与对照组比较,C4、IgA明显升高(P<0.05);而IgM升高、C3和IgG降低(P>0.05)。其中IgM与D8S1179-12、D19S433-16.2位点明显相关(P<0.05),IgG与FGA21位点明显相关(P<0.05)。结论 COPD患者免疫学指标发生变化,推测IgM、IgG检测结果与基因位点有关联,可能由基因决定了免疫学指标的个体差异性。     

PPMP调控KBv200细胞株mdr1基因表达逆转其多药耐药

为研究糖脂合成酶抑制剂苯基棕榈酰胺吗啡丙醇（DL-threo-1-phenyl-2-palmitoylamino-3-morpholino-1-propanol     

The polymorphisms of fucosyltransferases

The alpha(1,2)fucosyltransferase Se enzyme regulates the expression of the ABH antigens in secretion. Secretors, who have ABH antigens in their saliva, have at least one functional Se allele in the FUT2 locus, while non-secretors, who fail to express ABH antigens in saliva, are homozygous for the non-functional se allele. Molecular analyses of the FUT2 polymorphism of various populations have indicated the ethnic specificity of null alleles: the null allele se(428) is a common Se enzyme-deficient allele in Africans and Caucasians but does not occur in Asians, whereas the null allele se(357,385) is specific to Asians. The gene frequency of se(428) or se(357,385) is about 0.5 in each respective population. Why the se(428) is absent in Asians is of interest. Also here, we describe the polymorphisms of the fucosyltransferase genes (FUT1, FUT3 and FUT6).     

α粒子诱发BEP2D细胞恶性转化中抗氧化能力和辐射敏感性研究

目的 研究α粒子诱发人支气管上皮细胞BEP2D恶性转化中细胞的抗氧化能力和辐射敏感性变化.方法 运用谷胱甘肽过氧化物酶(GPX)、过氧化氢酶(CAT)和谷胱甘肽(GSH)试剂盒分别检测永生化人支气管上皮细胞BEP2D、α粒子作用BEP2D后第21代细胞RH21和α粒子作用BEP2D细胞后形成的恶性转化细胞BERP35T-1内抗氧化酶GPX和CAT的活性以及抗氧化剂GSH的含量;四甲基偶氮唑盐比色(MTT)法检测0、30、60、90、120和150 μmol/L H2O2作用BEP2D、RH21和BERP35T-1细胞96 h后,细胞增殖率的差异;0、2、4和8 Gy γ射线照射BEP2D、RH21和BERP35T-1细胞7～9 d后,用细胞克隆计数和MTT法检测细胞增殖率和存活分数的变化.结果 RH21和BERP35T-1细胞中GPX酶活力均低于BEP2D细胞(t=5.75和7.65,P＜0.05).BEP2D细胞中CAT酶活力是RH21细胞的2.64倍,是BERP35T-1细胞的5.76倍.RH21细胞中GSH含量与BEP2D细胞比较,差异无统计学意义;恶性转化细胞BERP35T-1内GSH含量则明显低于BEP2D细胞(t=7.76,P＜0.05).与BEP2D细胞相比,60、90、120和150 μmol/L H2O2作用后RH21细胞的增殖率降低(t=29.90～84.68,P＜0.01),30、60、90、120和150 μmol/L H2O2作用后BERP35T-1细胞的增殖率降低(t=10.37～58.36,P＜0.01).4和8 Gy γ射线照射后,RH21细胞的增殖率和存活分数均显著低于BEP2D细胞(t=6.33～45.00,P＜0.05);2、4和8 Gy γ射线照射后,BERP35T-1细胞的增殖率和存活分数较BEP2D细胞明显降低(t=5.87～34.17,P＜0.05).结论 α粒子诱发人支气管上皮细胞BEP2D恶性转化过程中,细胞的抗氧化能力降低、辐射敏感性增强.抗氧化系统功能减弱可能是α粒子诱发BEP2D细胞恶性转化和辐射敏感性增强的机制之一.

Abstract：

Objective To investigate the antioxidant ability and radiosensitivity in the malignant transformed human bronchial epithelial cell line BEP2D induced by α-particle exposure.Methods Glutathione Peroxidase (GPX),Catalase (CAT) and Glutathione (GSH) assay kits were employed to detect GPX and CAT enzyme abilities and the levels of GSH in BEP2D,RH21 ( passage 21 of α-particle-irradiated BEP2D cells),and BERP35T-1 cells (derived from nude mice bearing malignant transformed cells generated from cells of passage 35 of α-particle-irradiated BEP2D cells).MTT assay were used to test the growth rate of BEP2D,RH21 and BERP35T-1 cells treated with 0,30,60,90,120,and 150 μmoL/L H2O2.Colony-forming test and MTT assay were used to examine the cell survival fraction and the growth rate of BEP2D,RH21 and BERP35T-1 cells exposed to 0,2,4,and 8 Gy of γ-rays,respectively.Results GPX and CAT enzyme activities in RH21 and BERP35T-1 cells were obviously lower than in BEP2D( t = 5.75-67.92 ,P ＜ 0.05 ).CAT enzyme activity in BERP35T-1 was lower than that in RH21 cells (t =22.25 ,P ＜0.01 ).Compared to BEP2D cells,decreased level of GSH was detected in BERP35T-1 cells(t = 7.76,P ＜ 0.05 ),but there was no change in RH21.After treatment with 30,60,90,120,and 150 μmol/L H2O2,the growth rates of BEP2D were all higher than those of BERP35T-1 cells(t = 10.37-58.36,P ＜0.01 ).Meanwhile,the growth rates of BEP2D were all higher than those of RH21 cells after treatment with 60,90,120,and 150 μ mol/L H2O2 (t = 29.90-84.68,P ＜ 0.01 ).In addition,compared to BEP2D cells,decreased cell survival fraction and growth rate of BERP35T-1 cells were observed after irradiation with 2,4,and 8 Gy of y-rays ( t = 5.87-34.17,P ＜ 0.05 ).The cell survival fraction and growth rate of RH21 were all lower than those of BEP2D cells at 4 and 8 Gy post-irradition( t =6.33- 45.00,P ＜ 0.05 ).Conclusion The function of antioxidant system decreased in the α-particleinduced transformed cells,which could contribute to the acceleration of cellular malignant transforming process and radiosensitivity.     

衰竭心肌组织基质金属蛋白酶-3表达与心功能损害的相关性研究

目的：探讨心肌组织基质金属蛋白酶-3（MMP-3）相对含量与心衰进程中心功能损害的相关性。方法：采用RT-PCR方法对31例风湿性心脏病（RHD）心力衰竭患者及8例健康人心室肌组织中MMP-3含量进行半定量分析；RHD患者术前心功能指标采用超声心动图检查；采用t检验及相关分析方法进行分析。结果：心功能越差，MMP-3相对含量越高；MMP-3含量与射血分数（EF），心指数（CI）呈显著负相关，结论：MMP-3表达含量的增加导致心肌重构，其参与了心衰的发生发展，是影响心衰患者心功能恢复的重要因素之一。     

Magnetic resonance (MR) cholangiography: quantitative and qualitative comparison of 3.0 Tesla with 1.5 Tesla

OBJECTIVES: To determine quantitative and qualitative image quality in patients undergoing magnetic resonance (MR) cholangiography at 3.0 Tesla (T) compared with 1.5 T. MATERIALS AND METHODS: Fifty patients (30 women; mean age, 51 years) underwent MR cholangiography at 1.5 T; another 50 patients (25 women; mean age 51 years) were scanned at 3.0 T. MR sequence protocol consisted of breath-hold single-slice rapid acquisition with relaxation enhancement (RARE) and a respiratory-triggered 3D turbo spin echo (3D TSE) sequence. Maximum intensity projections were generated from the 3D TSE datasets. Contrast-to-noise ratio (CNR) measurements between the common bile duct (CBD), left and right intrahepatic duct (LHD, RHD), and periductal tissue were performed. Three radiologists assessed qualitatively the visibility of the CBD, LHD, and RHD and the overall diagnostic quality. RESULTS: Mean gain in CNR at 3.0 T versus 1.5 T in all 3 locations ranged for the RARE sequence from 7.7% to 38.1% and for the 3D TSE from 0.5% to 26.1% (P > 0.05 for all differences). Qualitative analysis did not reveal any significant difference between the 2 field strengths (P > 0.05). CONCLUSIONS: MR cholangiography at 3.0 T shows a trend toward higher CNR without improving image quality significantly.     

我国登革2型病毒43株基因组全长cDNA体外RNA转录物感染性的研究

目的：研究我国登革２型病毒４３株（Ｄ２－４３）基因组全长ｃＤＮＡ体外ＲＮＡ转录物的感染性,为进一步阐明登革２型病毒的致病机制及探索其新型疫苗奠定基础。方法：用ＳＰ６ＲＮＡ聚合酶系统制备Ｄ２－４３基因组全长ｃＤＮＡ的体外ＲＮＡ转录物,纯化后经电穿孔法转染Ｃ６／３６细胞,观察致细胞病变作用以判断其感染性。从病变的细胞和培养上清中提取总ＲＮＡ,通过ＲＴ－ＰＣＲ扩增及克隆测序的方法证实细胞病变确为ＲＮＡ转录物感染所致;同时收集可产生细胞病变的培养上清,再感染Ｃ６／３６细胞以进一步证实该体外ＲＮＡ转录物感染的稳定性。结果：以我国Ｄ２－４３病毒株基因组全长ｃＤＮＡ为模板制备的体外ＲＮＡ转录物可使Ｃ６／３６细胞产生病变,从病变细胞和培养上清中可扩增获得病毒特异的基因片段。在培养细胞中进行连续传代仍可产生细胞病变作用。结论：构     

Porcelain heart

Rheumatic heart disease (RHD) was the leading-cause of death in individual aged 5-20 years a century ago. Developments in diagnosis and treatment, decreased the incidence of RHD and dropped its mortality-rate to less than 10% since the 1960s. Despite the existence of proven preventive strategies in early detection and management of rheumatic fever (RF), RHD remained the most common cause of cardiovascular-mortality and morbidity in patients with RF. Previous studies have showed that Jones criteria may have insufficient support to diagnose patients with RF. Patients with subclinical, ongoing, and unrecognized episodes of RF may present late to medical attention with complication of RF such as indolent carditis. Recent studies revealed the superior role of echocardiography, as compared with clinical screening to diagnose subclinical RHD. While valvular involvement and ventricular dysfunction of RHD can be easily detected with echocardiography and magnetic resonance imaging (MRI), it remains problematic to determine the presence of whether there is myocardial-calcification after rheumatic heart carditis and if yes, how much extent it involves. The current case-report suggests the superior role of computed tomography angiography (CTA), as compared with echocardiography and MRI, to diagnose RHD in individuals without known history of RF. CTA with high spatial-resolution accurately evaluates tissue characterization and simultaneous assessment of the anatomy and function of heart and coronaries, and can precisely differentiate RHD from other cause of porcelain heart. The use of CTA in RHD screening provides the opportunity to initiate secondary antibiotic prophylaxis to prevent the poor outcome of rheumatic heart disease.     

应用PCR-反向点杂交法检测β-地中海贫血基因点突变

目的对疑似β-地中海贫血的4例患者进行基因诊断。方法针对β-珠蛋白基因上17个位点突变,使用特异性带有生物素标记的引物进行PCR扩增,扩增产物与固定在膜条上的寡核苷酸探针进行杂交,并通过一系列显色反应,明确检测样品在17个位点是否发生了突变,以及是否为突变纯合子或杂合子。结果 1号和2号患者均为CD17M（A→T）/N,βEM（GAG→AAG）/N双重杂合子;D3号患者为IVS-Ⅱ-654M（C→T）/N杂合子;D4号患者为IVS-Ⅱ-654M/IVS-Ⅱ-654M（C→T）纯合子。结论利用PCR-反向点杂交法技术,能对β-地中海贫血患者进行基因诊断,对其产前诊断、临床治疗以及携带者检出具有重要意义。     

鲁中南地区汉族ABO、Rh等主要血型系统抗原分布调查

目的　调查研究鲁中南地区汉族人群ABO、Rh等主要血型系统抗原分布状况。方法　采用血型群体遗传学研究方法 ,随机选择鲁中南地区汉族人群 2 172人 ,进行ABO、Rh、MN、P血型系统的表现型及基因频率分布调查分析。结果　(1)ABO血型表现型频率顺序B >O >A >AB ,基因频率r >q >p ,民族指数 =0 .88。 (2 )A2 表现型频率为 1.0 2 %。(3)Rh血型表现型以CCDee、CcDE多见 ,基因组合体频率CDe(0 .6 812 )最高。(4 )MN血型基因频率m =0 .4 95 1,n =0 .5 0 4 9。(5 )P血型基因频率P1 =0 .12 2 3,P2 =0 .8777,结论　鲁中南地区汉族人群ABO、Rh等主要血型系统抗原分布状况与北方汉族人群血型抗原分布特征基本相符     

大肠癌组织大肠癌缺失基因杂合缺失的研究

采用聚合酶链反应（ＰＣＲ）和限制性片段长度多态性分析（ＲＦＬＰ）技术，对４１例大肠癌组织大肠癌缺失基因杂合性缺失进行研究。结果表明，３８例大肠癌信息个体中有２１例（５５．３％）发现ＤＣＣ基因杂合缺失。ＤＣＣ基因杂合性缺失与肿瘤大小、组织学类型和浸润深度无关，但有淋巴结转移（８０．００％）和ＤｕｋｅｓＣ、Ｄａｄｗｅ（７１．４％）大肠癌ＤＣＣ基因杂合缺失率显著高于无淋巴结转移（３９．１％）和Ｄｕｋｅｓ     

No association between variants in the ACE and angiotensin II receptor 1 genes and acute mountain sickness in Nepalese pilgrims to the Janai Purnima Festival at 4380 m

Koehle, Michael S., Pei Wang, Jordan A. Guenette, and Jim L. Rupert. No association between variants in the ACE and angiotensin II receptor 1 genes and acute mountain sickness in Nepalese pilgrims to the Janai Purnima Festival at 4380 m. High Alt. Med. Biol. 7:281-289, 2006.--Acute mountain sickness (AMS) causes significant morbidity among visitors to altitude. The primary contributors to developing AMS are altitude and rate of ascent; however, the substantial variation in susceptibility between individuals has led a number of investigators to propose that there may be genetic predilection to the disease. The ACE I/D polymorphism has been shown to predict performance among elite mountaineers. This study compares genotype and allele frequencies at the ACE I/D locus, two other loci in the ACE gene, and one locus in the angiotensin-2 receptor gene between individuals who did, or did not, express signs of AMS while attending a high altitude religious festival in Nepal (4380 m). Subjects (80 males, 23 females) were recruited and genotyped. All subjects were Nepalese. Forty-four of the subjects had been diagnosed with AMS by physicians at a high altitude health camp; the rest were free from altitude illness. All subjects were genotyped at polymorphic loci in the genes encoding angiotensin converting enzyme (ACE) and angiotensin II receptor type 1 gene (AGTR1). The polymorphisms examined were two single nucleotide polymorphisms (SNPs) in ACE (ACE(A-240T), dbSNP rs4291; and ACE(A2350G), dbSNP rs4343), the intronic Alu insertion in ACE (ACE I/D), and the SNP ATR(A1166C), (dbSNP rs17231380) in AGTR1d. All polymorphisms in ACE were found to be in linkage disequilibrium. No significant associations were found between AMS incidence and any of the alleles, suggesting that variants at these loci do not contribute to susceptibility to AMS in this population.     

Null alleles and sequence variations at primer binding sites of STR loci within multiplex typing systems

Rare variants are widely observed in human genome and sequence variations at primer binding sites might impair the process of PCR amplification resulting in dropouts of alleles, named as null alleles. In this study, 5 cases from routine paternity testing using PowerPlex^®21 System for STR genotyping were considered to harbor null alleles at TH01, FGA, D5S818, D8S1179, and D16S539, respectively. The dropout of alleles was confirmed by using alternative commercial kits AGCU Expressmarker 22 PCR amplification kit and AmpFℓSTR^®. Identifiler^® Plus Kit, and sequencing results revealed a single base variation at the primer binding site of each STR locus. Results from the collection of previous reports show that null alleles at D5S818 were frequently observed in population detected by two PowerPlex^® typing systems and null alleles at D19S433 were mostly observed in Japanese population detected by two AmpFℓSTR™ typing systems. Furthermore, the most popular mutation type appeared the transition from C to T with G to A, which might have a potential relationship with DNA methylation. Altogether, these results can provide helpful information in forensic practice to the elimination of genotyping discrepancy and the development of primer sets.     

军队427名汉族官兵Rh血型抗原分布调查分析

目的调查部队汉族官兵Rh血型抗原分布,提高军队医院临床输血水平。方法采用血型群体遗传学研究方法,选择参加无偿献血汉族官兵427名,进行Rh血型表现型及基因频率检测研究。结果(1)表现型频率顺序为CCDee>ccDE>CcDE>ccDee>CCDE>CcDee>ccdee;(2)基因频率为D>d,C>c,e>E;(3)组合体频率以CDe(R1)0.6178为最高。结论部队汉族官兵Rh血型抗原分布研究,对提高军队医院临床输血水平及建立完善战备血液采供体系,具有重要意义。     

Sequence analysis and population data of short tandem repeat polymorphisms at loci D8S639 and D11S488

Short tandem repeat loci are ideal markers for forensic and paternity case work. A high degree of polymorphism, as determined by gross length measurement, is very often due to complex underlying sequence variation. In the present study, we have studied the sequence structure and population genetics of two short tandem repeat polymorphisms at loci D8S639 and D11S488 in German Caucasians from the region of Hesse. Sequence data revealed a considerable polymorphism at both loci. Locus D8S639 is characterized by a tetranucleotide (AGAT)n repeat pattern with (GAT) and (AGGT) repeats dispersed throughout several alleles. These microvariations lead to alleles differing by one base pair or alleles of identical size. At locus D8S639 we observed 17 allelic lengths comprising 25 different alleles. Alleles at locus D11S488 possess a compound repeat region consisting of (AAAG)n and (GAAG)n repeats. At locus D11S488 we observed 15 allelic lengths with a total of 24 alleles. Allelic lengths increased in size by 4bp increments corresponding to the addition of one tetranucleotide repeat unit. Population data of loci D8S639 and D11S488 revealed a high polymorphism with heterozygosity rates of 0.85 (D8S639) and 0.91 (D11S488). Received: 18 September 1997 / Received in revised form: 23 March 1998