Two new mutations and three novel polymorphisms in the<Emphasis Type="Italic"> RB1</Emphasis> gene in Ecuadorian patients

RB1 is the gene responsible for retinoblastoma, the most common malignant intraocular tumor of infancy and early childhood. There are no reports about this gene in Ecuadorian populations, and only a few studies have been published in Latin America about this subject. There is a spectrum of more than 370 mutations described in the RB1 gene mutation database (http://www.d-lohmann.de/Rb/mutations.html), and alterations have been found in 25 of the 27 exons. During the exon-by-exon analysis of 31 tumor and blood samples from Ecuadorian patients, we found two new mutations and three novel polymorphisms. One of the polymorphisms is located in intron 26 where no alterations of the gene have been described previously. The polymorphisms were found in all of the patients tumor samples, but not in normal population, suggesting there might be a relationship between these polymorphisms and the development of retinoblastoma in the Ecuadorian population.The nucleotide sequence data reported are available in the GenBank database under the accession numbers: AY243567, AY260472, AY260473, AY273783     

Polymorphic Alu Insertions and their Associations with MHC Class I Alleles and Haplotypes in the Northeastern Thais

Polymorphic Alu insertions (POALINs) are known to contribute to the strong polymorphic nature of the Major Histocompatibility Complex (MHC). Previous population studies on MHC POALINs were limited to only Australian Caucasians and Japanese. Here, we report on the individual insertion frequency of the five POALINs within the MHC class I region, their HLA‐A and ‐B associations, and the three and four locus alpha block POALIN haplotype frequencies in the Northeastern (NE) Thai population. Of the five POALINs, the lowest frequency was 0.018 for AluyHF and the highest frequency was 0.292 for AluyHJ and AluyHG. The strongest positive associations between the POALINs and HLA class I alleles was between AluyMICB and HLA‐B*57, AluyHJ and HLA‐A*24 and HLA‐A*01, and AluyHG and HLA‐A*02, supporting previous findings in Caucasians and Japanese. Single POALIN haplotypes were found more frequently than multiple POALIN haplotypes. However, of the seven different POALIN haplotypes within the MHC alpha block, there were only two significant differences between the NE Thais, Caucasians and Japanese. This study confirms that the MHC POALINs are in linkage disequilibrium with HLA‐A and –B alleles and that there are significant frequency differences for some of the POALINs when compared between NE Thai, Caucasians and Japanese.     

用Amp—Flp方法分析D1S80位点多态性

目的：为了解广西壮族人群D1S80位点群体遗传资料,方法,使用扩增片段长度多态性（Amp-Flp)和PCR结合聚丙烯酰胺凝电脉及银染技术,对300名文本地区壮族无关个体D1S80位点多态性分析,结果,观察到23个等位基因,74个基因型,杂合度,非交排除率,个体识别力及多态信息含量分别为0.824,0.763,0.968,0.875,其基因频率分布符合Hardy-weinberg定律,对5个家系相关个体分析符合孟德尔定律,结认,该方法具有快速,简便,特异性强,灵敏度高特点。     

多巴胺D2受体基因启动子A-241G多态性在精神分裂症家系中的连锁不平衡传递

目的:探讨多巴胺D2受体基因(dopamine D2 receptor,DRD2)启动子A-241G多态性与精神分裂症的关系.方法:采集101个家系,每家有2名或2名以上符合ICD-10精神分裂症诊断标准患病同胞且父母存活.对DRD2启动子的A-241G多态性进行检测.结果:(1)DRD2启动子的A-241G等位基因频度和基因型频度在父母组、非患病同胞组和患病同胞组之间差异无显著性,在3组不同性别之间以及在精神分裂症不同亚型之间基因型频度和等位基因频度的分布差异亦无显著性;(2) 传递不平衡检验发现在患病同胞(χ2 =0.94,P>0.05,OR=0.83,95%可信区间0.57～1.21)中未表现传递不平衡性,而在非患病同胞(χ2 =6.76,P<0.01,OR=3.17,95%可信区间0.41～24.71)中存在传递不平衡性,其中-241A等位基因在非患病同胞中传递较多;(3) 基因型与妄想总分、幻觉总分、思维形式障碍、情感障碍、精神性失语及症状持续时间等临床特征相关.结论:DRD2启动子的A-241G多态性对精神分裂症的发病和临床表现具有一定影响.     

成都地区汉族人群ACE基因多态性与血清ACE活性的相关性

为调查中国汉族人群血管紧张素转换酶(ACE) 基因多态性分布及与血清ACE(SA CE)活性的相关性.采用比色法和PCR技术,对90例健康汉族人群进行SACE活性和ACE基因插入/缺失(I/D)多态性的检测.结果显示:中国汉族人群ACE基因DD型占18%,DI型占44%,II 型占38%, D和I等位基因频率分别为0.40和0.60.ACE基因多态性与SACE活性密切相关,提示不同种族间ACE基因分布存在着差异,中国汉族人群ACE基因多态性以II型和I等位基因占优势;SACE活性受ACE基因I/D多态性的影响.     

凉山彝族男性血管紧张素转换酶基因多态性与高血压的关系

目的　探讨血管紧张素转换酶（ＡＣＥ） 基因多态性与高血压的关系。方法　应用横断面调查方法和ＰＣＲ 技术。结果　正常血压人群ＡＣＥ 基因ＤＤ、ＩＤ 和ＩＩ基因型分别占１３ ．０ ％ 、５０ ．９ ％ 和３６ ．１ ％ 。Ｉ和Ｄ等位基因频率分别是为６１ ．６ ％ 和３８ ．４ ％ 。高血压人群ＡＣＥ 基因ＤＤ、ＩＤ 和ＩＩ基因型分别占９ ．７ ％ 、４８ ．４ ％ 和４１ ．９ ％ 。Ｉ和Ｄ 等位基因频率分别是６６ ．１ ％ 和３３ ．９ ％ 。彝族男性高血压和正常血压人群的ＡＣＥ基因型分布及Ｉ／Ｄ 等位基因频率差异无显著性。结论　彝族男性ＡＣＥ 基因多态性与高血压的关联尚不能确定。     

中国汉族人群遗传性聋基因座位STR位点的遗传多态性研究

目的 研究中国汉族人群10个遗传性聋基因座位的短串连重复序列(STR)的遗传多态性。方法 应用PCR方法对10个位点进行扩增，变性聚丙烯酰胺凝胶电泳分离，记录基因型。采用PPAP软件计算正常人各STR位点等位片段频率、基因型频率、预期基因型频率、多态信息量(PIC)和Hardy-Weinberg平衡吻合性检验。结果 中国汉族人群D6S287、D8S1132、D13S1275、D15S130、D1S2726、D4S3038、D2S2380、D22S282、D14S1042、D7S529各位点分别检出10个、9个、8个、7个、7个、7个、6个、6个、6个及5个等位片段，多态性分布均符合Hardy-Weinberg平衡定律。各位点PIC值分别为0．879、0．854、0．864、0．821、0．686、0．794、0．764、0．732、0．773、0．712；杂合度均高于0．7。结论 中国汉族人群10个位点STR均具有较高的杂合度和多态信息量，是较理想的遗传标记。     

Subjects with <Emphasis Type="Italic">TNF-A-857TT</Emphasis> and <Emphasis Type="Italic">-1031TT</Emphasis> genotypes showed the highest <Emphasis Type="Italic">Helicobacter pylori</Emphasis> seropositive rate compared with those with other genotypes

Background A possible association between Helicobacter pylori seropositivity and tumor necrosis factor (TNF) A G-308A has been reported in Korea. The present study examined the associations of H. pylori with functional polymorphisms, TNF-A G-308A, C-857T, and T-1031C, and TNF-B A252G in Japanese subjects.Methods The total of 1374 study subjects included 241 outpatients who participated in an H. pylori eradication program (HPE), 679 first-visit outpatients (FVO) at a regional cancer hospital, and 454 local residents who received a health checkup examination (HCE).Results The frequency of the TNF-A -308A allele was only 1.3% of 480 chromosomes in the HPE group, so the FVO and HCE groups were not genotyped for that polymorphism. The genotype frequency of TNF-A C-857T was 69.2% CC, 27.7% CT, and 3.1% TT; that of TNF-A T-1031C was 69.4% TT, 28.1% TC, and 2.5% CC; and that of TNF-B A252G was 36.8% AA, 48.2% AG, and 15.0% GG. TNF-A -857T was tightly linked to TNF-A -1031T and TNF-B 252A. No significant associations between H. pylori seropositivity and polymorphisms of TNF-A C-857T and TNF-B A252G were observed. However, a reduced odds ratio adjusted for sex, age, and recruitment source was observed for TNF-A -1031CC (0.43; 95% confidence interval, 0.20–0.91) relative to TNF-A -1031TT. Subjects with TNF-A -857CC and -1031CC showed the lowest seropositivity (38.2% of 34 participants), while those with TNF-A -857TT and -1031TT showed the highest (66.7% of 42 participants).Conclusions This study suggests that the possibly high expression genotype of TNF-A may increase susceptibility to persistent H. pylori infection.     

AP-PCR和set1、set2两基因PCR用于志贺菌基因多态性研究

目的与方法 :　应用随机引物 PCR(简称 AP- PCR或 PAPD)和 set1、set2两基因 PCR方法分析了 71株F2 a志贺菌的基因多态性。　结果 :两种引物的 AP- PCR中 ,引物 12将 71株 F2 a志贺菌分为两种不同的基因型 ,引物 17和 set1、set2两基因 PCR将所有菌株分为四种不同的基因型 ,两种方法结合则可分为七种不同的基因型 ;其中 6 5株 F2 a志贺菌基因型相同 ,其余 6株各为独立的型别。本研究表明 AP- PCR和 set1、set2两基因 PCR为志贺菌基因多态性分析的有效手段 ,二者结合则更为完善 ;研究结果还表明 ,在我国南北不同地区不同时间分离到的无论是暴发株还是散发株 ,均具有相同的优势克隆。　结论 :上述菌株是引起国内菌痢散发和暴发的主要基因型 ,是流行病学研究和防治的重点     

应用DHPLC技术分析错配修复基因(hMLH1)T1151A多态与胃肠道肿瘤的遗传易感性

目的了解中国人hMLH1基因T1151A多态与胃肠道肿瘤的遗传易感性.方法采用病例对照研究设计,提取233例大肠癌(结,直肠癌)患者,273例胃癌患者和268例健康人外周血细胞的基因组DNA.PCR扩增hMLH1基因T1151A多态所在第12外显子的部分DNA片段(217 bp),变性高效液相色谱(DHPLC)检测,DNA测序验证,比较分析T1151A基因型在胃肠道肿瘤的分布.结果正常人群中T1151A多态T/A基因型频率为6.34%,其等位基因A频率为3.28%,在大肠癌患者和胃癌患者中T/A基因型频率与正常人群相比存在显著性差异,分别为11.6%(P=0.039)和12.1%(P=0.021),尤其在＜45岁的大肠癌患者和＜50岁的胃癌患者中,等位基因A频率与正常人群相比差异更为显著,分别为10.66%(P=0.002)和11.27%(P=0.001).结论T1151A作为中国人hMLH1基因上的一个多态位点,可能是中国人大肠癌和胃癌遗传易感因素,可作为中国人胃及大肠肿瘤、尤其是低龄胃及大肠肿瘤高危人群筛选的侯选指标.