良性家族性婴儿惊厥疾病基因与染色体8q24的连锁分析

目的 :对 5例中国良性家族性婴儿惊厥 ( BFIC)家系进行基因定位研究。方法 :选择 D8S50 2 、D8S537等 STR作为 DNA标记 ,应用聚合酶链反应 ( PCR) ,变性聚丙烯酰胺凝胶电泳 ( PAGE)和银染技术 ,采用 LINKAGE软件包中的 MLINK程序进行连锁分析。结果 :在常染色体显性 ( AD)模式下 ,在标记位点 D8S50 2 处 ,5个家系在重组率为 0 .0 5 0 ,外显率为 70 %时 ,获得两点对数优势计分 ( LOD)值总和为 0 .337;在标记位点 D8S537处 ,5个家系在外显率为 70 % ,重组率从 0 .0 0 0到 0 .40 0之间 ,获得两点 L OD值总和均为负值。结论 :不能认为位点D8S50 2 和 D8S537与 BFIC疾病基因存在连锁关系     

良性家族性婴儿惊厥疾病家系位点D18S460和D18S474连锁分析

目的:对5个中国良性家族性婴儿惊厥(benign familial infantile convulsion,BFIC)家系进行基因定位研究.方法:选择D18S460、D18S474等短串联重复序列(STR)作为DNA标记,应用聚合酶链反应(PCR),变性聚丙烯酰胺凝胶电泳(PAGE)和银染技术,采用LINKAGE软件包中的MLINK程序进行连锁分析.结果:在常染色体显性(AD)模式下,在标记位点D18S460和D18S474,5个家系在重组率为0.000,外显率从90%到50%时,获得两点对数优势计分(log odds score,LOD)值总和均为-∞;在标记位点D18S474处,5个家系在重组率为0.400,外显率为70%时,获得最大两点LOD值总和仅为0.002.结论:位点D18S460和D18S474与BFIC疾病基因不存在连锁关系.     

全面性癫痫伴热性惊厥附加症家系致病基因的连锁定位和突变分析

目的 筛查中国全面性癫痫伴热性惊厥附加症(GEFS+)家系的致病基因.方法 采集2个GEFS+家系所有成员的外周静脉血提取基因组DNA,选取GEFS+的候选基因(SCN1B、SCN1A、SCN2A和GABRG2)附近10个微卫星位点用于遗传连锁分析,连锁分析所用的软件为LINKAGE软件包5.1版,根据两点间的LOD值判断连锁关系,以确定两家系致病基因的大致位置.限定性定位后筛选候选致病基因,并对家系所有成员进行候选基因突变分析.结果 标记SCN1A、SCN2A和SCN1B基因的多个微卫星位点在两家系患者中均没有共享等位基因,基本排除两家系与上述3个基因连锁可能.田氏家系在标记GABRG2基因的微卫星位点D5S820、D5S422和D5S1403均有共享等位基因.经两点间连锁分析,在外显率为70%,重组率为0时,D5S820、D5S422和D5S1403处的LOD值分别为0.67,1.00和0.79,提示可能有连锁关系.邸氏家系仅在标记GABRG2基因的微卫星位点D5S1403有共享等位基因.对两家系GABRG2基因9个外显子测序结果 显示,第5号外显子出现一个单核苷酸同义多态位点(c.588C>T),第3号外显子出现一个单核苷酸多态位点(c.604C>T),第7号外显子的非编码区出现一个单核苷酸多态位点,为G/A杂合性改变,未发现GABRG2基因致病突变.结论 我国新发现的两个GEFS+家系的致病基因与目前已知候选基因SCN1B、SCN1A、SCN2A和GABRG2无关.GEFS+家系的常见致病基因仍不清楚.     

常染色体显性遗传性先天性白内障一家系致病基因的初步定位

目的 初步定位常染色体显性遗传性先天性白内障(ADCC)一家系的致病基因。方法 收集ADCC一家系资料，在已知先天性白内障致病基因和位点附近，选择合适的短串联重复序列多态性标记(STRP)，对ADCC一家系进行连锁分析，使用Mlink软件采用对数优势记分法(LOD)计算LOD值。结果 在STRP中，D17S805、D17S1294及D17S1293与致病基因位点连锁的最大IDD值分别为2．03、2．49及2．22(重组率θ=0)。结论 该ADCC家系的致病基因初步定位在第17对染色体上；CRYBA1基因为候选基因。     

瘢痕疙瘩家系17号染色体易感基因位点的定位分析

目的定位中国汉族瘢痕疙瘩家系的易感基因位点。方法采集2个4代发病的中国汉族瘢痕疙瘩家系51名成员的外周静脉血样,提取基因组DNA;假定p53基因为该瘢痕疙瘩家系易感基因位点,选取位于17号染色体区域的10个微卫星标记位点D17S849,D17S938,D17S1852,D17S799,D17S921,D17S1857,D17S1868,D17S787,D17S949,D17S784,对这些微卫星位点进行PCR扩增,产物片断基因分型,再进行连锁分析。结果在重组率θ=0~0.5时,这些微卫星标记的两点LOD值绝大部分都小于1,可以排除连锁关系存在。结论研究发现中国汉族瘢痕疙瘩家系易感基因位点不在17号染色体区域。     

瘢痕疙瘩家系17号染色体易感基因位点的定位分析研究

目的 定位中国汉族瘢痕疙瘩家系的易感基因位点。方法 采集2个4代发病的中国汉族瘢痕疙瘩家系51名成员的外周静脉血样，提取基因组DNA；假定p53基因为该瘢痕疙瘩家系易感基因位点，选取位于17号染色体区域的10个微卫星标记位点D17S849, D17S938, D17S1852, D17S799, D17S921, D17S1857, D17S1868, D17S787, D17S949, D17S784，对这些微卫星位点进行PCR扩增，产物片断基因分型，再进行连锁分析。结果　在重组率θ=0～0.5时，这些微卫星标记的两点LOD值绝大部分都小于1，可以排除连锁关系存在。结论　研究发现中国汉族瘢痕疙瘩家系易感基因位点不在17号染色体区域。     

毛囊闭锁三联征一家系致病基因精细定位研究

目的 对1例毛囊闭锁三联征家系进行连锁分析精细定位研究,确定其致病基因位点.方法 应用覆盖1号染色体1p21.1～1q25.3区域的17个微卫星标记对该家系进行基因分型、连锁分析和单倍型分析.结果 在1号染色体上的微卫星标记DIS2 707处获得最大LOD值为2.11(重组率θ=0.00).通过单倍型分析将该家系致病基因定位在微卫星标记D1S2 715和D1S484之间的染色体1q21.3～1q23.2区域.结论 该研究提示1p21.1～1q25.3(61.8cM)是毛囊闭锁三联征致病基因连锁区域,并将致病基因支持连锁范围缩小至1q21.3～1q23.2(9.8 cM)区域.     

银屑病易感基因位点的检测

目的：寻找中国人群银屑病的易感基因位点。方法：选取19个多态性微卫星标记,采用由荧光标记PCR、MegaBACE测序仪和与之配套的Genetic Profiler分析软件建立的荧光标记的自动基因分型体系对38个银屑病家系中的银屑病患者与亲属的外周血白细胞中提取的DNA进行 基因扫描,并用参数和非参数分析方法进行连锁分析。结果：在参数连 锁分析中,D6S1610的最大两点连锁（LOD值）为1．18（θ＝0．2）,D17S944的两大两点LOD值为1．60（θ＝0．1）;在非参数单点和多点连锁分析中,D6S1610、D17S944和D17S785的单点非参数（NPL）值均大于1．6,相应P值也小于0．05。结论：位点D6S1610、D17S944和D17785可能与中国人群银屑病相连锁。     

家族性局灶节段性肾小球硬化的基因研究

目的:探讨家族性局灶节段性肾小球硬化(familial focal segmental glomerulosclerosis, FFSGS)基因与染色体1q25-31区域的连锁关系.方法:1个中国皖北地区3代FFSGS家系,采集本家系中27名成员的外周血样,选择位于1q25-31上的10微卫星标志:D19S49、D1S452、D1S242、D1S416、D1S240、D1S254、D1S202、D1S222、D1S238和D1S413,应用聚合酶链式反应(PCR)得到扩增产物片断,采用ABI PRISMTM310 Genetic Analyze 测定 PCR产物片断大小.利用Genescan 软件( 3.1 版)、Genetyper ( 3.7版) 处理后得到检测片断大小,根据相应微卫星标记的产物片断大小不同,得到每个样本的基因型.对基因型数据进行校对后,用连锁分析软件 LINKAGE 的 MLINK 程序计算每个标记的两点间LOD(log odds)值.根据两点LOD值判断连锁关系.结果:连锁分析结果显示所有微卫星标记两点间LOD值在不同重组率时均小于0,所有LOD值在重组率为0.0时均小于-2,说明该FFSGS家系疾病基因与1q25-31区域没有连锁关系.结论:该家族疾病基因与已报道的FFSGS 定位区域(1q25-31区域)没有连锁关系.     

全身性癫痫伴高热惊厥附加症2个家系致病基因连锁定位分析

目的：研究全身性癫痫伴高热惊厥附加症致病基因连锁定位分析。方法：分析2个家系患者的临床表现特征,并进行基因连锁分析。结果：患者的发作类型、频率及持续时间均不相同。在D5S1480及D5S1471的微卫星标记处,在不同重组率时LOD值在0～2．0。在两个微卫星标记之间新增加了5对微卫星标记(D5S1500,D5S820,D5S1403,D5S1476,D5S1386),进一步进行连锁分析。结果存D5S1500、D5S820处LOD值均大于3．0(θ=0．00);提示有肯定连锁关系。结论：患者存在着表型异质性;全身性癫痫伴高热惊厥附加症致病基因在5q34区域,     

Linkage analysis of five Chinese families with arrhythmogenic right ventricular cardiomyopathy using microsatellite genetic markers

Objective To explore the linkage relationship between specific genetic markers and arrhythmogenic right ventricular cardiomyopathy (ARVC) in Chinese pedigrees. Methods The microsatellite genetic markers D2S152, D14S252, and D10S1664 were studied for their linkages to ARVC in five Chinese ARVC pedigrees and a normal population of 121 Chinese individuals. Genomic DNA of the pedigrees and normal population was amplified using PCR techniques. Denaturing polyacrylamide sequencing gel (4%) electrophoresis was used to detect microsatellite repeat polymorphisms. Gels were silver-stained. A classical linkage analysis program was used assuming models of autosomal dominance and recession. Results The logarithm of the odds (LOD) scores of D2S152 with ARVC in LW, WD, DS, LC and TY pedigrees were 2.174, －0.589, －∞, － （indicating that linkage is not supported in this mode）, and －∞ respectively in autosomal dominant model （recombination fraction=0.000 respectively）and were －∞, －∞, －∞, －∞, and 0.182 respectively in the autosomal recessive model. The LOD scores of D14S252 with ARVC in LW, WD, DS, LC and TY pedigrees were －, －, －∞, －, and 0 respectively in autosomal dominant model, and were －∞, －0.812, －∞, －∞, and 0.087 respectively in autosomal recessive model. The LOD scores of D2S152 with ARVC in LW, WD, DS, LC and TY pedigrees were －, －0.539, －, and 0.602 respectively in autosomal dominant model and were －, －∞, －∞, －∞, and －∞ respectively in autosomal recessive model. Conclusions The LOD score for D2S152 in the LW pedigree was 2.174, indicating that the chance of linkage is about 150∶1. This suggests that there is a possible ARVC-related gene near this marker. There were no clear linkage relationships between ARVC and D10S1664 and D14S252 in this family, and no linkages between ARVC and any of the three genetic markers in the other four families. These results also suggest that there is genetic heterogeneity in LW and in the other pedigrees.     

Gene mapping of autosomal dominant retinitis pigmentosa in a Chinese family

Background The autosomal dominant form of retinitis pigmentosa （ADRP） can be caused by mutations in 14 genes and further loci remains to be identified. This study was intended to identify mutations in a Chinese pedigree with ADRP.
Methods A large Chinese family with retinitis pigmentosa was collected. The genetic analysis of the family suggested an autosomal dominant pattern. Microsatellite （STR） markers tightly linked to genes known to be responsible for ADRP were selected for linkage analysis. Exons along with adjacent splice junctions of PRPF31 were amplified by polymerase chain reaction （PCR） and screened by direct sequencing.
Results The caused gene of ADRP was mapped to 19q13.4 between markers D19S572 and D19S877, with a maximum LOD score of 3.01 at marker D19S418 （recombination fraction=0）.
Conclusion The affected gene linked to the 19q13.4 in a Chinese family with ADRP, which is different from other mutations at the same loci in other Chinese families.     

A novel candidate locus on chromosome 11p14.1-p11.2 for autosomal dominant hereditary spastic paraplegia

Background Hereditary spastic paraplegia （HSP） is a group of inherited neurodegenerative disorders with the shared characteristics of slowly progressive spasticity and weakness of the lower limbs. Thirteen loci for autosomal dominant HSP have been mapped. Methods A Chinese family with HSP was found in the Shandong province and Inner Mongolia Autonomous Region of China and genomic DNA of all 19 family members was isolated. After exclusion of known autosomal dominant loci, a genome wide scan and linkage analysis were performed. Results The known autosomal dominant loci of SPG3A, SPG4, SPG6, SPG8, SPG9, SPG10, SPG12, SPG13, SPG17, SPG19, SPG29, SPG31 and SPG33 were excluded by linkage analysis. The results of a genome wide scan demonstrated candidate linkage to a locus on chromosome 11 p14.1-p11.2, over an 18.88 cM interval between markers D11 S1324 and D11 S1933. A maximal, two point LOD score of 2.36 for marker D11S935 at a recombination fraction （e） of 0 and a multipoint LOD score of 2.36 for markers D11S1776, D11S1751, D11S1392, D11S4203, D11S935, D11S4083, and D11S4148 at θ=0, suggest linkage to this locus. Conclusion The HSP neuropathy in this family may represent a novel genetic entity, which will facilitate discovery of this causative gene.     

应用遗传连锁分析法对伴传导功能障碍的扩张型心肌病家系致病基因的定位

目的: 对一个常染色体显性遗传扩张型心肌病(familial dilated cardiomyopathy,FDCM)家系进行基因定位。方法: 收集FDCM 家系, 对该家系成员进行详细心血管内科检查确诊为扩张型心肌病,且伴发有传导功能障碍;采集外周血3～5 mL,并抽提基因组DNA;选取与该表型相关的已定位区间CMD1A(1q21.2-q21.3),CMD1H(2q14-q22), CMD1E(3p22-p25)和CMD1F(6q22-23)内的共计18个微卫星DNA标记,在该家系中进行排除性定位分析;最后,进行全基因组扫描及连锁分析。结果：①已定位区间的18个微卫星DNA标记位点的LOD值均<-2,证实该家系与已知DCM位点不连锁;②全基因组扫描及两点连锁分析结果显示,该家系致病基因位点与遗传标记D3S1614(3q26)连锁, 在θ= 0时得到最大LOD值2.68。结论: 该家系与已知的4个DCM位点均不连锁,其致病基因位于D3S1614（3q26）附近的一个新位点。     

Familial Wolff-Parkinson-White syndrome is linked to the locion chromosome 7q3

Objective Wolff-Parkinson-White syndrome (WPW) is considered to be an autosomal dominanthereditary disease, but the gene is not identified. The objective of this study was to localize the genetic loci of Wolff-Parkinson-White syndrome. Methods Linkage analysis between the disease of Wolff-Parkinson-White syndrome and 3 STR (short tandem repeats) markers on 7q3 (D7S505, D7S688, and D7S483) was tested in 3 kindreds of the Wolff-Parkinson-White syndrome (101 numbers in total) by genotyping. Results Wolff-Parkinson-White syndrome was linked to the loci above. The maximum two-point Lod score detected at D7S505 was 6. 4 at a recombination fraction (θ) of 0. 1; the Lod score of D7S688, D7S483 was 5. 3 vs 2. 5. Conclusion The gene of Wolff-Parkinson-White syndrome is located at 7q3.     

Autosomal dominant coralliform cataract related to a missense mutation of the γD-crystallin gene

Background Congenital cataract is a sight-threatening disease that affects about 1 -6 cases per 10 000 live births and causes 10% -30% of all blindness in children. About 25% of all cases are due to genetic defects. We identified autosomal dominant congenital coralliform cataracts-related genetic defect in a four-generation Chinese family.Methods Complete ophthalmological examinations were performed prior to lens extraction. Lens samples were then studied by electron microscopy. Genomic DNA from family members were examined using whole-genomic linkage analysis, with two-point logarithm of odds (LOD) scores calculated using the Linkage program package (version 5. 1 ). Mutation analysis of candidate genes was performed by direct sequencing. Finally, a three-dimensional protein model was predicted using Swiss-Model (version 2.0).Results Eleven of the 23 examined individuals had congenital cataracts. Ultrastructure studies revealed crystal deposits in the lens, and granules extensively dispersed in transformed lens fiber cells. The maximum two-point LOD score, 3. 5 at θ = 0. 1, was obtained for the marker D2S,325.Mutation analysis of the γ-crystallin (CRYG) gene cluster identified a mutation (P23T) in exon 2 of γD-crystallin (CRYGD). Protein structure modeling demonstrated that the P23T mutation caused a subtle change on the surface of the γD protein.Conclusions The results suggest that the coralliform cataract phenotype is due to a mutated CRYGD gene, and that this sequence change is identical to one reported by Santhiya to be related to another distinct clinical condition, lamellar cataract. This study provides evidence that this same genetic defect may be associated with a different phenotype. This is the first report identifying the genetic defect associated with an autosomal dominant congenital coralliform cataract.     

β3肾上腺能受体基因与肥胖、糖尿病、胰岛素抵抗关系的家系水平研究

目的 :研究肥胖、2型糖尿病、胰岛素抵抗与 β3 AR基因之间的关系及其在家系遗传中的规律。方法 :运用PCR RFLP技术分析了 8个肥胖伴糖尿病家系的 β3 AR基因外显子 64位色氨酸 /精氨酸 (tryptophantoarginineTrp64Arg)多态性。 结果 :β3 AR基因与肥胖进行连锁 ,在常染色体显性遗传模式下 ,单个家系 (家系 3 )最大LOD值为 3 .88510 9(θ =2 0 .0 0 0 0 0 )。将 β3 AR基因与 2型糖尿病进行连锁 ,在常染色体显性遗传模式下 ,单个家系 (家系 2 )LOD最大值为 0 .2 2 2 3 3 6(θ =0 .0 0 0 0 0 0 ) ,在常染色体隐性遗传模式下 ,单个家系(家系 4)LOD最大值为 0 .80 5 0 0 3 (θ =0 .0 0 0 0 0 0 0 )。结论 :Trp64Arg多态性改变是部分家系肥胖产生的直接原因     

Mapping of a gene for severe pediatric gastroesophageal reflux to chromosome 13q14

CONTEXT: Gastroesophageal reflux (GER) has not previously been widely regarded as a hereditary disease. A few reports have suggested, however, that a genetic component may contribute to the incidence of GER, especially in its severe or chronic forms. OBJECTIVE: To identify a genetic locus that cosegregates with a severe pediatric GER phenotype in families with multiple affected members. DESIGN: A genome-wide scan of families affected by severe pediatric GER using polymorphic microsatellite markers spaced at an average of 8 centimorgans (cM), followed by haplotyping and by pairwise and multipoint linkage analyses. SETTING: General US community, with research performed in a university tertiary care hospital. SUBJECTS: Affected and unaffected family members from 5 families having multiple individuals affected by severe pediatric GER, identified through a patient support group. MAIN OUTCOME MEASURES: Determination of inheritance patterns and linkage of a genetic locus with the severe pediatric GER phenotype by logarithm-of-odds (lod) score analysis, considering a lod score of 3 or greater as evidence of linkage. RESULTS: In these families, severe pediatric GER followed an autosomal dominant hereditary pattern with high penetrance. A gene for severe pediatric GER was mapped to a 13-cM region on chromosome 13q between microsatellite markers D13S171 and D13S263. A maximum multifamily 2-point lod score of 5.58 and a maximum multifamily multipoint lod score of 7.15 were obtained for marker D13S1253 at map position 35 cM when presumptively affected persons were modeled as unknown (a maximum multipoint score of 4.88 was obtained when presumptively affected persons were modeled as unaffected). CONCLUSION: These data suggest that a gene for severe pediatric GER maps to chromosome 13q14. JAMA. 2000;284:325-334     

一常染色体显性遗传寻常型鱼鳞病家系致病基因的定位

目的 研究一常染色体显性遗传寻常型鱼鳞病家系的致病基因。方法 采用基因组扫描方法,利用1号染色体上的微卫星标记对该家系进行连锁分析,然后对候选基因FLG的部分编码区及外显子与内含子交界处进行突变检测。结果 在D1S2696得到最大两点连锁LOD值3．46（0=0）,单体型分析将疾病基因定位在D1S2726-D1S305之间约15cM范围内;在FLG基因的外显子非重复序列及部分重复序列未发现与疾病相关的突变。结论 该寻常型鱼鳞病家系的致病基因位于D1S2696附近,其致病基因可能是除FLG以外的其他基因。