Association analysis of polymorphisms in the upstream region of the human dopamine D4 receptor gene (DRD4) with schizophrenia and personality traits

The human dopamine D4 receptor (DRD4) is of major interest in molecular studies of schizophrenia and personality traits. We examined the association of schizophrenia and polymorphisms in the upstream region of the DRD4 gene (−768G>A in the negative modulator region; −521C>T, −376C>T, and −291C>T in the cell type-specific promoter region; and −616C>G between the two regions) in 208 schizophrenic patients and 210 normal controls. No significant difference in genotype and allele frequencies was observed between the two groups, indicating that these polymorphisms do not make a major contribution to the pathogenesis of schizophrenia. We also studied the association of polymorphisms in the upstream region and a 48-bp repeat polymorphism in exon III of the DRD4 gene with personality traits in 173 Japanese individuals who completed the temperament and character inventory (TCI). The −768G>A polymorphism was significantly associated with reward dependence (P = 0.044), while no significant association was observed between novelty seeking and polymorphisms in the upstream region or the exon III repeat polymorphism of the DRD4 gene. Received: August 28, 2000 / Accepted: October 25, 2000     

人巨细胞病毒UL136基因在临床低传代分离株中多态性分析

目的 研究人巨细胞病毒(human cytomegalovirus，HCMV)UL136基因在临床低传代分离株中的多态性，探讨其多态性与HCMV先天性感染不同致病性之间的关系。方法 对48株经荧光定量PCR方法检测HCMV DNA为阳性的临床低传代分离株进行HCMV ULl36全序列PCR扩增，对于扩增阳性的12株PCR产物进行ULl36基因全序列测定及结果分析。结果 48株临床低传代分离株ULl36 PCR扩增，12株阳性，阳性率25％，以HCMV Toledo株作为参考株，进行序列比较分析表明，12株临床分离株ULl36开放阅读框架(open reading frame，ORF)长度均与Toledo株相同，为723bp，编码241个氨基酸的蛋白。DNA序列变异均为碱基替换，不同临床分离株ULl36基因与Toledo株进行同源性比较，结果在核苷酸水平为97．7％～99．3％，氨基酸水平为96．6％～99．1％。ULl36编码蛋白的氨基酸变异率为0．83％～3．3％。二级结构预测分为两种构象。大多数HCMV ULl36蛋白翻译后修饰位点在所有分离株中均高度保守，仅几个位点在一些分离株中存在缺失或新增。Toledo株及12株临床分离株核苷酸及氨基酸序列系统进化树分析表明：45J最接近Toledo株。结论 12株临床低传代分离株HCMV ULl36基因DNA及其编码产物的氨基酸序列比较保守，但仍存在一定多态性。未发现不同临床分离株ULl36基因多态性与HCMV先天性感染的表现关系。     

河南汉族人群亚甲基四氢叶酸还原酶基因多态性

目的了解河南汉族人亚甲基四氢叶酸还原酶(methylenetetrahydrofolate reductase,MTHFR)基因的分布特点。方法应用PCR-RFLP技术对500例健康个体的MTHFRC677T基因进行基因多态性分析,并结合文献进行了不同种族间的分析比较。结果河南汉族人群中MTHFRC677T突变纯合子TT型频率为32.8%,突变杂合子CT型频率为34.6%,野生型CC型频率为32.6%,T等位基因频率51.1%,与其他种族相比较,MTHFRC677T基因型在中国河南汉族正常人群中的分布与其他人群中的分布差异显著。结论MTHFRC677T基因多态性在不同种族间分布存在着明显的差异。     

Polymorphisms in the human CYP1A1 gene as susceptibility factors for lung cancer: exon-7 mutation (4889 A to G), and a T to C mutation in the 3′-flanking region

Genetic differences in the metabolism of carcinogens may codetermine individual predisposition to cancer. Cytochrome P-4501A1 (CYP1A1) metabolically activates precarcinogens in cigarette smoke, such as benzo(a)pyrene, which is also an inducer of CYP1A1. Two point mutations have been reported, m1 in the 3-flanking region (6235T to C), and m2 within exon 7 (4889A to G), the latter leading to an isoleucine to valine exchange. In the Japanese population ml and m2 are correlated with lung cancer, suggesting an increased susceptibility to cigarette smoking related lung cancer. We studied 142 lung cancer and 171 reference patients in an ethnically homogeneous German group for m1 and m2 mutations by restriction fragment length polymorphism and allele-specific polymerase chain reaction, respectively. No statistically significant difference was found in the distribution of m1 alleles between lung cancer and controls; the frequency was 8.5% and 7.3% of the alleles, respectively (odds ratio = 1.17). A trend to an overrepresentation of ml alleles was observed among 52 squamous cell carcinoma patients (odds ratio = 1.65). In contrast, the frequency of m2 alleles in lung cancer patients was twofold higher (6.7%) than in the reference group (3.2%; odds ratio = 2.16; 95% confidence limits 0.96–5.11, P = 0.033); the odds ratio of m2 alleles in squamous cell carcinoma was 2.51 (95% confidence limits 0.85–7.05, P = 0.05). There was a close genetic linkage of m2 to m1 (10 of 11 reference patients), but a significantly higher number of cancer patients showed no linkage compared to the controls (odds ratio = 8.89, 95% confidence limits 0.83–433, P = 0.04). Thus no association was found between presence of ml alleles and lung cancer, but, in contrast, m2 alleles proved as a hereditary risk factor, especially if not linked with m1 alleles.Abbreviations Ah aryl hydrocarbon - CYP1A1 cytochrome P4501A1 - CYP1A1 CYP1A1 gene - PCR polymerase chain reaction - PY pack years - RFLP restriction fragment length polymorphism Correspondence to: N. Drakoulis     

Genotypes of autosomal dominant polycystic kidney disease in Japanese

Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common hereditary disorders. The prevalence of the ADPKD genotype in the Caucasian and Latin populations has been reported. Here, we used linkage analysis to demonstrate the prevalence of the genotype and the correlation between phenotypes and genotypes among 21 Japanese ADPKD families consisting of 96 individuals and including 57 affected members. Six polymorphic markers, each linked to either the polycystic kidney disease 1 (PKD1) or polycystic kidney disease 2 (PKD2) gene, were used for polymerase chain reaction analysis. Seventeen families (81%) showed linkage to PKD1, two families (10%) showed linkage to PKD2, and two families did not show linkage to either PKD1 or PKD2. One of the PKD1-linked families was indicated to have different mutations of PKD1 gene in the same family. PKD2-linked families did not have milder symptoms than PKD1-linked families. Received: October 9, 2001 / Accepted: November 9, 2001     

Association of essential hypertension in elderly Japanese with I/D polymorphism of the angiotensin-converting enzyme (ACE) gene

Recent evidence suggests that an insertion/deletion (I/D) polymorphism of the gene encoding angiotensin-converting enzyme (ACE) is associated with myocardial infarction and related cardiovascular diseases. We investigated a possible association of the ACE polymorphism with essential hypertension in a total of 263 cases/controls from among the elderly (age, over 70 years) and middle-aged (age between 30 and 60 years) Japanese population. The frequency of the I/I homozygote was significantly higher in hypertensive subjects than in controls in the elderly age group (33/57 vs 16/46; P = 0.02), but no association was observed in the middle-aged group (25/75 vs 26/85; P = 0.71). Similarly, having at least one insertion allele was associated with essential hypertension in the elderly age group (83/114 vs 46/92 in controls; P = 0.001), but not in the middle-aged group (78/150 vs 94/170; P = 0.524). These data suggest that genetic variation at the ACE locus may be associated with some determinants for blood pressure in elderly persons, and imply the involvement of the ACE insertion/deletion polymorphism in the etiology of age-related essential hypertension in the Japanese population. Received: April 18, 2000 / Accepted: July 25, 2000     

Iα1基因hs1,2 区B等位基因与IgA肾病的易感性相关

［摘要］ 目的：研究Iα1 hs1,2 VNTR多态性与我国IgA肾病的相关关系。 方法： 采集419例肾活检证实的IgA肾病患者及其一级亲属、条件相当的201例健康志愿者血样，提取基因组DNA。用PCR产物直接电泳法鉴定Iα1 hs1,2 VNTR基因型，采用以家庭为基础的传递/不平衡分析（TDT）和单倍型相对危险度（HRR），以及病例-对照研究分析Iα1 hs1,2 VNTR多态性与我国IgA肾病的相关关系。 结果： ① TDT分析结果显示Iα1 hs1,2 VNTR B等位基因从杂合子父母向患者传递的频率显著高于预期值(101 Trios, χ2=6.818, P＜0.01，扩展TDT分析也得到相同结果(164家庭, χ2=7.583, P＜0.01)。②与TDT结果一致，HRR分析同样显示Iα1 hs1,2 VNTR B等位基因的过度传递 (P＜0.05, χ2=4.122, HRR=1.180)， 而BB基因型具有更强的患病倾向 (P＜0.05, χ2=4.411, OR=1.538)。③病例-对照研究显示IgA肾病组B 等位基因频率显著高于正常对照组(χ2=6.968, P＜0.05)。 结论： Iα1 hs1,2 VNTR基因多态性与我国IgA肾病患者的易感性相关。     

G蛋白β3亚单位基因C825T多态性与PTCA支架内再狭窄

目的 探讨G蛋白β3亚单位基因C825T多态性与PTCA支架植入后再狭窄之间的相关性。方法 采用多聚酶联反应结合限制性内切酶片断长度多态性分析方法(PCR-RFLP)检测50例经PTCA支架植入术后半年内发生再狭窄的患者和85例经PTCA支架植入在半年内未发生再狭窄的患者之间G蛋白β3亚单位基因C825T多态性。结果 再狭窄组G蛋白β3亚单位基因型频率(CC 14％、CT 54％、TT 32％),等位基因频率(C 41％、T 59％)与未狭窄组G蛋白β3亚单位基因型频率(CC31.8％、CT 44.7％、TT 23.5％),等位基因频率(C 54.2％、T 45.8％)比较统计学上有差异。结论 G蛋白β3亚单位基因C825T多态性可能与PTCA支架内再狭窄有关。     

广东汉族人蛋氨酸合成酶基因多态性

目的了解广东汉族人蛋氨酸合成酶基因的分布特点.方法应用聚合酶链反应技术对211例正常人蛋氨酸合成酶基因进行扩增,进行图谱分析.并结合文献进行了不同种族间的分析比较.结果广东汉族人群中MS基因型以AA最多见,AG次之.AA基因型频率为0.8009、AG为0.1802、GG为0.0189.A基因型频率为0.8910、G为0.1090.与其他种族相比较,MS基因型在中国正常人群中的分布与白种人群中的分布差异显著.结论蛋氨酸合成酶基因因多态性在不同种族间分布存在着明显的差异.     

Familial Alzheimer disease associated with A713T mutation in APP

Mutations in APP are associated with familial early-onset Alzheimer disease (FAD). Examination of the genomic sequence in one patient with FAD revealed a change located in the axon 17 of the APP gene at position 275329G>A (GenBank accession number: D87675; GI: 2429080); cDNA sequence 2137G>A (GenBank accession number: X06989; GI: 28720). This corresponds to the mutation A713T in APP. AD stage VI of neurofibrillary degeneration and stage C of Aβ-amyloid burden was found at the post-mortem neuropathological examination. Previous studies have suggested that the mutation A713T in APP is a silent mutation or polymorphism. However, we have not found this change in APP in a control population analyzed by the amplification-refractory mutation system (ARMS). It is concluded that A713T in APP is implicated in the pathogenesis of AD. Since the immunohistochemical study indicates that A713T mutation is not likely to relate with Aβ-amyloid processing, the causative role of this rare mutation remains to be warranted.