DXS52(St14)在血友病甲基因诊断中的方法改进及应用

目的 改进DXS52(St14)在血友病甲(hemophilia A,HA)基因连锁分析中的实验方法并应用于基因诊断,报道DXS52位点与FⅧ基因发生重组的2个家系.方法 采用PCR和琼脂糖凝胶电泳对61个非倒位HA家系的DXS52位点进行基因检测,并用FⅧ基因内的Bcl Ⅰ、HindⅢ、Xba Ⅰ、STRl、STRl3、STR22和STR24这7个位点以及DXS52位点对这61个家系进行基因连锁分析.结果 DXS52位点在43个HA家系中可提供信息,可诊断率为70.5%(43/61).其中8个家系仅DXS52单个位点能提供信息,占13.1%;两个家系的DXS52与FⅧ基因发生基因重组.结论 采用新的实验条件可使DXS52位点基因检测得到准确清晰的实验结果.该位点可诊断率高,目前是HA连锁基因分析中不可缺少的诊断位点,但该位点位于FⅧ基因外,与FⅧ基因间存在重组可能,单独应用于诊断时应谨慎.

Abstract：

Objective To improve the experimental method of DXS52 (St14) and apply it to genetic testing for hemophilia A (HA). Methods PCR of DXS52 and agarose gel electrophoresis were performed for genetic testing in 61 non-inversion HA families. Linkage analysis of 7 loci within the FⅧ gene including Bcl Ⅰ , Hind Ⅲ, Xba Ⅰ , STR1, STR13, STR22 and STR24 were also carried out for the 61 families.Results DXS52 can provide information in 43 out of 61 families and the diagnostic rate was 70. 5%. Eight families can be diagnosed only by DXS52 locus, accounting for 13. 1%. Two families were found to have recombination between DXS52 and FⅧ. Conclusion The new experimental conditions can reach accurate and clear results in DXS52 genetic testing. This gene maker has high diagnostic rate, so it is an indispensable linkage analysis method in HA gene diagnosis. More caution should be paid when using the extragenic locus DXS52 to perform gene diagnosis because of its high recombinant rate with FⅧ.     

Hemophilia A: genetic prediction and linkage studies in all available families in Finland

RFLP studies were done in 82 (75%) of all known hemophilia A families in the Finnish population (approximately 5 million). Two intragenic RFLPs (Bc1I/F8A, XbaI/p482.6) and two extragenic markers (TaqI/St14, Bg1II/DX13) were used. Among 263 females at risk, carriership could be evaluated with an intragenic marker in 47% and with an extragenic marker in 26%. In 27% of the females, carriership could be neither excluded nor confirmed; 68% of these females were relatives of an isolated patient. Eight recombinations between the factor VIII gene (F8C) and DXS52 (lod 25.02 at theta max 0.06), eight recombinations between F8C and DXS15 (lod 21.91 at theta max 0.05), and two recombinations between DXS52 and DXS15 (lod 33.56 at theta max 0.01) were found. Using multipoint linkage analysis, the most likely order of loci supported by the data was: F8C-DXS15-DXS52-DXS134. RFLP segregation analysis provides a highly useful method of carrier detection and prenatal diagnosis of hemophilia A, but its limitations must be carefully taken into account.     

血友病甲基因分析技术的改进及其在产前诊断中的应用

目的对血友病甲基因分析技术进行改进并应用于携带者检查和产前诊断。方法长距离聚合酶链反应方法直接检测凝血因子Ⅷ第22内含子倒位,对非倒位家系用FⅧ基因内限制酶切位点XbaⅠ、HindⅢ、二核苷酸重复序列多态性位点STR13和STR22,以及基因外可变数目串联重复序列DXS52(St14)位点进行基因连锁分析。结果52个家系共检出71位携带者。21个家系为第22内含子倒位,28个家系经连锁分析得到明确诊断,3个家系无法诊断,可诊断家系占94.2%。为18个家系做胎儿产前诊断,其中10例诊断为血友病甲胎儿;诊断7例正常男胎和1例携带者女胎,随访1年发育正常。结论应用长距离聚合酶链反应和多位点基因连锁分析技术可以快速有效地进行血友病甲携带者检查和产前诊断。     

A detailed restriction endonuclease cleavage map of rat liver mitochondrial DNA

Summary A restriction endonuclease cleavage map of rat liver mitochondrial DNA is presented for the following enzymes: Xba I, Bgl II, Hae II, Bam HI, Hpa I, Hha I, Bcl I, Hind II, Hind III, Eco RI, Hpa II, Hae III, and Sau 3A. It was derived from complete and partial digestions with these enzymes, double digestions, and redigestions of defined fragments obtained with one enzyme with other restriction enzymes. By the use of these and further enzymes (Taq YI, Alu I) the mitochondrial DNA (ca. 15.6 Kb) can be dissected into a large number of defined fragments.Abbreviations mtDNA mitochondrial DNA - bp or Kbp base pairs or kilo base pairs     

Cleavage maps of human cytomegalovirus genome (strain towne) determined by the use of cosmid cloning system

Summary Virion DNA of human cytomegalovirus strain Towne was partially digested with endonuclease Hind III and fragments larger than 29 kbp were ligated to cosmid pHC79. The whole viral DNA sequence has been cloned in large overlapping segments carried by 32 recombinant cosmid clones (a pIT series). A whole set of Hind III fragments has also been cloned (a pHI series). By using these, we have constructed corrected cleavage maps of strain Towne DNA for Hind III, Bam H I, EcoR I and Xba I.With 4 Figures     

N-ras-like sequences on chromosomes 9, 6 and 22 with a polymorphism at the chromosome 9 locus

Two clones, pCN1 and pCN2, which together form full-length cDNA for N- ras , were used to search for restriction fragment length polymorphisms. pCN2, which entirely consists of 3' non-translated sequences, revealed more bands on DNA transfer hybridizations than could be accounted for using the known restriction map of N- ras. None of the extra cross hybridizing sequences is located on chromosome 1. One of these sequences showed a high-frequency two-allele polymorphism with the restriction enzyme Taq I and maps to the short arm of chromosome 9. Of the remaining two sequences, one maps to chromosome 22 and the other maps to the short arm of chromosome 6. pCN1A, which contains the 5' untranslated regions and all the coding exons of N- ras only hybridized to the chromosome 1 site. No polymorphisms have been found for pCN1 with Taq I, Msp I, Bcl I, Bgl I, EcoR I, Bst XI, Xba I, Bam HI, Bgl II or Hind III.     

The degree of genetic variability among adenovirus type 4 strains isolated from man and chimpanzee

Summary A total of 8 different genome types of adenovirus type 4 (Ad 4), Ad 4 p, Ad 4 p 1–3, Ad 4 a, Ad 4 a 1, Ad 4 b, and Ad 4 ch were identified among 50 selected human adenovirus isolates and 2 chimpanzee adenovirus strains using 16 restriction endonucleases Bam HI, Bcl I, Bgl I, Bgl II, Bst EII, Dra I, Eco RI, Eco RV, Hind III, Hpa I, Sal I, Sma I, Ssp I, Pst I, Xba I, and Xho I. They could be divided into three genomic clusters. Cluster 1 contained Ad 4 p and Ad 4 p 1–3; cluster 2 contained Ad 4 a, ad 4 a 1 and Ad 4 b; whereas the chimpanzee Ad 4 genome type was the unique member of cluster 3. The degree of genetic variability within each cluster was minor. The genome types within one cluster display 95–99% pairwise comigrating restriction fragments (PCRF). However, the genetic space between the three clusters was large. The genome types between different clusters share only 25–46% PCRF. A comparative PCRF analysis performed with restriction endonucleases Apa I, Nar I, Nae I, Sac II, and Sma I recognizing exclusively G and C sequences and Dra I, Ssp I recognizing exlusively A and T containing sequences revealed that G and C rich regions were significantly more conserved than A and T rich regions.     

Fabry disease: Molecular carrier detection and prenatal diagnosis by analysis of closely linked polymorphisms at Xq22.1

Fabry disease is an X-linked recessive inborn error of glycosphingolipid catabolism that results from the deficient activity of the lysosomal enzyme α-galactosidase A (α-Gal A). A rapid, reliable, and universal linkage method was developed for molecular carrier detection and prenatal diagnosis. By determining the informativeness and phase of amplifiable intragenic RFLPs (NcoI and SacI), flanking RFLPs (DXS94 and DXS17), and flanking microsatellite polymorphisms at Xq22.1 (DXS458, DXS454, DXS7424, DXS178, and DXS101), accurate carrier detection, and/or prenatal diagnosis was accomplished in three prototypic, unrelated Fabry families. All linkage diagnoses were confirmed by identification and analysis of the specific α-Gal A lesion in each family. Thus, molecular carrier detection and prenatal diagnoses can be performed rapidly and reliably by linkage analysis with intragenic and closely-linked polymorphisms at Xq22.1 in Fabry families whose specific Gal A lesions have not been determined. Am. J. Med. Genet. 71:329–335, 1997. © 1997 Wiley-Liss, Inc.     

Carrier detection of Hunter syndrome (MPS II) by biochemical and DNA techniques in families at risk.

DNA based and biochemical diagnosis of MPS II was performed on 13 unrelated families using Southern blotting. The 35S-sulphate accumulation in cultured fibroblasts was investigated and the iduronate-2-sulphatase (IDS) activity in the serum determined. Sixteen patients and 36 females at risk were screened for structural aberrations and by RFLP analysis using the intragenic probe pc2S15 and probes VK23B, VK21A, and II-10 for the flanking loci DXS297, DXS296, and DXS466. Structural alterations were found in the DNA of two patients. One of them showed a major deletion including the whole coding sequence of the IDS gene. An aberrant Southern fragment occurred in the HindIII/pc2S15 blot of the other patient suggesting a new HindIII restriction site by point mutation in an IDS gene intron. Twenty-nine females were confirmed as carriers, and for five women the heterozygous state could be excluded. Prenatal diagnosis can be offered to 27 women if requested.     

Frequencies of five genetic polymorphisms in coronarographed patients and effects on lipid levels in a supposedly healthy population

Allele frequencies of genetic polymorphisms were compared between supposedly healthy subjects and angiographically proven coronary artery disease patients. The polymorphic candidate loci investigated were the apolipoprotein (apo) B signal peptide and Xba I polymorphisms, the apo E polymorphism and two polymorphisms of lipoprotein lipase (LPL) gene: Hind/ III and PvuII. Apo B signal peptide and Hind III/LPL polymorphisms showed significant differences in allele partition between cases and controls; the rare alleles of both polymorphisms were less frequent (p<0.05) in cases. We looked for associations between the polymorphisms and lipid concentration variability in a supposedly healthy population (145 men and 144 women). Apo B signal peptide, apo E and Pvul II/LPL polymorphisms seem to influence some lipid metabolism parameters significantly. Apo AI and LpCIII levels were significantly different among apo B signal peptide genotypes: Del homozygotes had the highest concentrations of both variables. The e4 allele of apo E polymorphism was associated with increased concentrations of total cholesterol, LDL cholesterol and apo B. Increased LpAI:AII levels observed in E3 homozygotes (p<0.01) have not previously been reported. LpAI:AII concentration was also influenced by Pvu II/LPL polymorphisms.     

抗人角蛋白全IgG基因真核表达载体的构建及表达

目的：构建抗角蛋白抗体基因的真核表达载体，并在CHO(dhfr^-)细胞中表达。方法：从含抗角蛋白抗体基因的原核Fab表达载体中，扩增VH及VL基因。以回收的PCR产物为模板，用重叠PCR扩增带有前导序列的VH、VL基因。经XbaⅠ/BamHⅠ和XhoⅠ/HindⅢ酶切后，分别插入真核表达载体pWD中，构建重组载体pWDkH。经PCR和测序鉴定正确后，用lipofectAMINE2000转染CHO(dhfr^-)细胞。取培养上清检测抗人角蛋白全IgG的表达。结果：构建了抗人角蛋白基因的真核表达载体pWDkH，并在CHO(dhfr^-)细胞中表达：结论：在CHO(dhfr^-)细胞中成功地表达了具有抗原结合活性的抗人角蛋白IgG，为其临床应用奠定了基础。     

Carrier detection of the fragile X syndrome with flanking RFLP markers and linkage analysis.

Linkage analysis was performed in 34 fragile X (fra(X)) families in order to study the efficiency of carrier detection using the restriction fragment length polymorphisms (RFLPs) closely linked to fra(X) locus (FRAXA). The marker loci used were F9, DXS105, DXS98, DXS369, DXS297 and DXS477 proximally and DXS465, DXS296, DXS304, DXS52 and F8C distally to FRAXA. Flanking heterozygosity was achieved in 60% of the females with a combination of 3 restriction enzymes and 6 closest RFLP markers. When adding more distant markers and other restriction enzymes to the analysis, the proportion of females heterozygous for flanking polymorphisms increased to 96%. With RFLP-analysis most (85/91) females at high risk of being a carrier could be separated clearly into 2 groups: those with a very low and those with a very high risk. The 6 cases with a recombination between flanking markers did not benefit from RFLP-analysis.     

Adrenoleucodystrophy: a molecular genetic study in five families.

A genetic study has been performed on five adrenoleucodystrophy families using DNA probes from Xq28. Members of each family had previously been tested for carrier status using the biochemical assay for very long chain fatty acids (VLCFAs), but several persons at risk had equivocal results. DNA analysis with four DNA probes St14-1 (DXS52), DX13 (DXS15), MN12 (DXS33), and hs7 showed no crossovers between them and the disease locus in persons who were clinically affected or had high levels of VLCFA or both. Thus, the genotypes provided by the DNA probes could be used for accurate carrier detection and prenatal diagnosis could be offered. Of the 17 at risk females with VLCFA levels in the normal (1 SD) range, five were defined as carriers and 12 were considered not to be.     

Physical maps for HSV type 2 DNA with five restriction endonucleases.

The ordering of restriction endonuclease fragments of HSV-2 DNA for physical maps has been studied using molecular hybridization techniques and the cleavage of isolated restriction endonuclease fragments with further restriction endonucleases. Physical maps for the fragments produced by EcoRI, Hind III, Bgl II, Xba and Hpa I have been constructed. The mol. wt. of the various regions which constitute HSV-2 genome are very similar to the corresponding mol. wt. in the HSV-1 genome.     

X染色体上六个短串联重复序列基因座遗传多态性研究

目的研究陕西西安汉族人群6个位于X染色体上的短串联重复序列：DXS7130、DXS1214、DXS6799、DXS6804、DXS7424和DXS7133等位基因及基因型频率分布。方法随机抽取陕西西安汉族118名女性和90名男性无关个体静脉血，提取DNA，PCR扩增，变性聚丙烯酰胺凝胶电泳，银染检测结果。结果在6个基因座中，DXS7130、DXS6799、DXS6804、DXS7424和DXS7133分别检出9个、6个、6个、7个和7个等位基因；SY别检出21、14、15、17和12种基因型；基因频率分别分布在0．0112～0．4101、0．0160～0．4840、0．0050～0．3713、0．0053—0．3632和0．0059～0．5235之间，DXS1214检出8个等位基因，基因频率分布在0．0104～0．3161之间；此6个位点女性的基因型频率分布均符合Hardy—Weinberg平衡。结论此6个X染色体短串联重复序列位点有较高的个体识别率，在个体识别和女孩的亲权鉴定中有应用价值，对疾病相关研究有实际意义。     

Linkage between the fragile X and F9, DXS52 (St14), DXS98 (4D-8) and DXS105 (cX55.7)

Linkage data using the markers F9, DXS105 (cX55.7), DXS98 (4D-8) and DXS52 (St14) are presented from 22 kindreds segregating with the fragile X. Two-point linkage analysis was carried out taking into account cytogenetic results and penetrance classes defined by mental impairment status of mothers. Recombination frequencies (theta) corresponding to the maximum z scores (z) were obtained between F9 (z = 3.48, theta = 0.18), DXS105 (z = 5.06, theta = 0.07), DXS98 (z = 4.79, theta = 0.01) and DXS52 (z = 6.44, theta = 0.09) and the fragile X. Recombination frequencies between marker loci in fragile X families are also presented. These recombination frequencies need to be combined with those from other studies in order to determine the best estimates of map distances for use in genetic counselling, until markers closer to the fragile X, or at the fragile X, can be used. Most potential fra(X) heterozygotes were informative for flanking markers using the above 4 probes. Carrier risks were determined by 3-point analysis using informative flanking markers, taking into account cytogenetic results. Low level fra(X) expression occurred in 2 probable non-carriers; emphasising the need for extreme caution in the interpretation of low rates of expression.     

雌激素受体-α基因Xba Ⅰ、 Pvu Ⅱ和BstU Ⅰ多态性与男性骨量的关系

目的 了解雌激素受体-α（estrogen receptor-α,ER-α）基因多态性与男性骨密度（bone mineral density,BMD）的关系。方法 PCR-限制性片段长度多态性检测上海市388名46－80岁无血缘关系的健康汉族男性ER-α基因XhaⅠ、Pvu Ⅱ和BstUⅠ多态性，双能X线吸收仪检查腰椎1－4（L1-4）和股骨近端股骨颈（femoral neck）、大转子区（trochanter）和Ward＇s三角部位BMD。结果 被研究人群XhaⅠ和Pvu Ⅱ等位基因频率分布符合Hardy-Weinberg定律。未发现ER-α基因第1外显子区存在BstUⅠ多态性，所有对象均是BB基因型。XhaⅠ多态性与各部位BMD值均无相关；Pvu Ⅱ多态性与L1-4和Ward＇s三角部位BMD值均有关联（P＜0.05），Pp基因型在上部位平均BMD值明显高于PP和pp基因型（P＜0.05）。结论 本研究结果提示中国汉族人群缺乏或罕有ER-α基因BstUⅠ多态性；ER-α基因PvuⅡ多态性可能影响老年男性松质骨骨量的丢失。     

小鼠MIP-1α真核表达质粒的构建及在HSV-Ⅱ核酸疫苗中的应用

目的：构建小鼠巨噬细胞炎性蛋白-1α（MIP-1α）的真核表达质粒,观察其作为分子佐剂对单纯疱疹病毒Ⅱ型（HSV-Ⅱ）DNA疫苗免疫效果的影响.方法：以LPS刺激RAW264.7细胞提取总RNA.采用RT-PCR扩增出MIP-1α基因的全部编码序列,利用克隆载体pUCm-T,将其亚克隆入pcDNA3中,构建出小鼠MIP-1α的真核表达质粒Pm;将其转染COS-7细胞,并用Boyden趋化小室法检测MIP-1α的生物学活性.然后用其与HSV-ⅡgD的DNA疫苗一起免疫BALB/c小鼠,检测免疫小鼠的特异性抗体、脾T细胞增殖反应及病毒攻击小鼠后对小鼠的保护率,观察MIP-1α对HSV-Ⅱ DNA疫苗免疫效果的影响.结果：成功构建了小鼠MIP-1α的重组真核表达质粒;免疫BALB/c小鼠发现,其作为分子佐剂可加强HSV-ⅡgDNA疫苗的免疫效果.结论：小鼠MIP-1α可作为HSV-Ⅱ gD DNA疫苗的分子佐剂,为研制新型有效的HSV-Ⅱ DNA疫苗提供一定的依据.     

X染色体四个STR基因座的遗传多态性及法医学意义

目的 建立X染色体短串联重复序列DXS7133、GATA198A10、DXS9896、DXS6797基因座的复合扩增系统，调查成都汉族人群的遗传多态性并探讨其法医学应用价值。方法 应用PCR和非变性聚丙烯酰胺凝胶电泳分型技术，并检验各基因座女性基因型频率分布是否符合hardy-Weinberg平衡，计算法医学常用各种概率。结果 DXS7133、GATA198A10、DXS9896、DXS6797基因座在成都地区汉族群体中(男100，女120)分别发现6、6、11、8个等位基因，女性个人识别几率分别达0．7962、0．8021、0．9675和0．9444。X^2检验表明各基因座女性的基因型频率分布符合Hardy-Weinherg平衡。32个亲子鉴定案例调查表明这4个基因座符合X染色体伴性遗传方式，未发现突变。结论 DXS7133、GATA198A10、DXS9896、DXS6797基因座在成都汉族群体中具有较高的遗传多态性，适用于个人识别和女孩的亲权鉴定。     

A novel locus for non-syndromic sensorineural deafness (DFN6) maps to chromosome Xp22

Non-syndromic X-linked deafness is highly heterogeneous. At least five different clinical forms have been described, but only two loci have been mapped. Here we report a Spanish family affected by a previously undescribed X-linked form of hearing impairment. Deafness is non- syndromic, sensorineural, and progressive. In affected males, the auditory impairment is first detected at school age, affecting mainly the high frequencies. Later it evolves to become severe to profound, involving all frequencies for adulthood. Carrier females manifest a moderate hearing impairment in the high frequencies, with the onset delayed to the fourth decade of life. Deafness was assumed to be X- linked dominant, with incomplete penetrance and variable expressivity in carrier females. The family was genotyped for a set of microsatellite markers evenly spaced at intervals of about 10 cM. We found evidence of linkage to markers in the Xp22 region (maximum lod score of 5.30 at theta = 0.000 for DXS8036 and for DXS8022). The position of the novel deafness locus (DFN6) was refined by haplotype analysis. Mapping of the breakpoints in two critical recombinants allowed us to define an interval for DFN6, delimited by DXS7108 on the distal side and by DXS7105 on the proximal side, and spanning a genetic distance of about 15 cM.