ALOX5AP和PDE4D基因与中国江苏南京地区腔隙性脑梗死发病的易感性：一项病例对照研究

The genes for 5-lipoxygenase activating protein (ALOX5AP) and phosphodiesterase 4D (PDE4D) have been demonstrated as susceptibility genes for lacunar in the Icelandic and Pakistani populations,but little is known about the role of these genes in Chinese populations.The present study utilized polymerase chain reaction and ligase detection reaction to detect single nucleotide polymorphisms (SNPs) in 280 consecutive stroke patients and 258 unrelated population-based controls from Nanjing,Jiangsu Province,China.The allele frequency,genotypes,and haplotypes of the two SNPs (rs456009 and rs966221) in PDE4D were similar between the two groups.However,A allele frequency of rs4073259 (A/G) and rs4769055 (A/C) in the ALOX5AP gene exhibited differences in two groups,and especially the haplotype of the SNP was significantly different between the two groups.Results suggested that the ALOX5AP gene might be involved in lacunar infarct,while PDE4D gene was not a risk factor for lacunar infarct in individuals from Jiangsu Province,China.     

5-脂氧合酶激活蛋白基因和白介素-1A基因多态与缺血性脑卒中的相关性

目的 探讨中国北方地区汉族人群5-脂氧合酶激活蛋白(ALOX5AP)基因和白介素-1A(IL-1A)基因多态与缺血性脑卒中(IS)的相关性.方法 采用病例-对照研究,检测构建ALOX5AP基因单倍型HapA的4个位点:SG13S25、SG13S32、SG13S89、SG13S114和IL-1A基因-889位点在对照组、IS组及IS亚组中多态的分布.结果 ALOXSAP基因SG13S114位点AA基因型可能是血栓性脑梗死独立的风险因素(OR=1.479,95% CI 1.024～2.135,P=0.037),且其风险性主要来源于A等位基因(OR=1.313,95% CI 1.017～1.693,P=0.036);IL-IA基因-889位点T等位基因可能是血栓性脑梗死的易患等位基因(OR=1.540,95% CI 1.075～2.204,P=0.023).HapA单倍型和IS没有相关性,GCGA单倍型可能是IS的危险单倍型(OR=1.683,95% CI 1.138～2.487,P=0.008).同时携带ALOX5AP基因GCGA单倍型和IL-1A-889T等位基因的个体患IS的风险性显著增加(OR=1.608,95% CI 1.607～2.423,P=0.022).结论 ALOXSAP基因、IL-1A基因的多态与IS具有相关性,二者的协同作用可显著增加IS的患病风险.     

Phosphodiesterase 4D and 5-lipoxygenase activating protein in ischemic stroke

Risk for ischemic stroke is mediated by both environmental and genetic factors. Although several environmental exposures have been implicated, relatively little is known about the genetic basis of predisposition to this disease. Recent studies in Iceland identified risk polymorphisms in two putative candidate genes for ischemic stroke: phosphodiesterase 4D (PDE4D) and 5-lipoxygenase activating protein (ALOX5AP). A collection of North American sibling pairs concordant for ischemic stroke and two cohorts of prospectively ascertained North American ischemic stroke cases and control subjects were used for evaluation of PDE4D and ALOX5AP. Although no evidence supported linkage of ischemic stroke with either of the two candidate genes, single-nucleotide polymorphisms and haplotypic associations were observed between PDE4D and ischemic stroke. There was no evidence of association between variants of ALOX5AP and ischemic stroke. These data suggest that common variants in PDE4D may contribute to the genetic risk for ischemic stroke in multiple populations.     

Meta-Analysis of Homogeneous Subgroups Reveals Association between PDE4D Gene Variants and Ischemic Stroke

Background: An Icelandic study showed a significant positive association between phosphodiesterase 4D (PDE4D) gene variants and stroke. However, subsequent studies reported conflicting results, possibly due to small sample sizes and the heterogeneity of the studies. Method: We performed a meta-analysis on 6 SNPs of the PDE4D gene to investigate the association between this gene and ischemic stroke by integrating the results of previous studies, comprising 11,834 cases and 15,233 controls. A pooled genotypic odds ratio (OR) for each SNP was determined under 3 genetic models (i.e. dominant, recessive, and codominant) using both fixed- and random-effects models with consideration for heterogeneity and publication bias across studies. Results: Among the SNPs included in this study, SNP56 (rs702553) showed the most significant association with ischemic stroke in a meta-analysis comprised of 7 homogenous studies. The overall OR of the TT genotype compared to the AA genotype was 1.29 (95% CI 1.03-1.61; p = 0.022). For SNP83 (rs966221), a protective effect of the ancestral allele T was observed only in Asian populations (ORTT 0.79, 95% CI 0.69-0.90; p = 0.0005). This meta-analysis revealed a significant association of PDE4D gene variants with the risk of ischemic stroke, and further investigations are warranted to evaluate possible ethnic-specific effects.     

A Novel Risk Haplotype of ALOX5AP Gene is Associated with Ischemic Stroke in Chinese Han Population

Previous studies have implicated that two at-risk haplotypes (HapA and HapB) of gene-encoding 5-lipoxygenase-activating protein (ALOX5AP) were significantly associated with stroke. The aim of this study was to explore the association between haplotypes of ALOX5AP gene and risk for ischemic stroke (IS) in Chinese Han population. A total of 492 patients with IS and 490 matched control subjects were recruited. Six ALOX5AP SNPs (SG13S377, SG13S114, SG13S41, SG13S89, SG13S32 and SG13S35) were genotyped by SNaPshot minisequence technique. A common genetic variant SG13S114/AA in the ALOX5AP gene was associated with IS in this Chinese cohort (OR?=?2.514, 95 % CI?=?1.667?~?3.790). HapA (TGA) and HapB (AAAG) had no significant difference in the patients (36.3 and 18.5 %, respectively) and controls (37.6 and 16.3 %, respectively) (P?=?0.631 and P?=?0.375, respectively). But, the frequency of Hap (GAAG) was significantly higher in the patients than that in the controls after Bonferroni's adjustment (P?=?0.006). To conclude, SG13S114/AA of the ALOX5AP gene was associated with an increased risk for IS. A novel risk haplotype, Hap (GAAG) was a genetic risk factor for IS in this Chinese population.     

Evaluation of single nucleotide polymorphisms in the phosphodiesterase 4D gene (PDE4D) and their association with ischaemic stroke in a large German cohort

Genetic fine mapping of the first locus identified for genetically complex forms of stroke, STRK1 (which has been mapped to chromosome 5q12 in Icelandic families), has identified the phosphodiesterase 4D gene (PDE4D) gene as a good candidate gene. Association analysis of single nucleotide polymorphisms (SNPs) in the PDE4D gene in an Icelandic stroke cohort demonstrated genetic association between six SNPs in the 5' region of PDE4D and ischaemic stroke. The present study aimed to test whether the same six SNPs in PDE4D were also associated with stroke in a large stroke cohort from northern Germany (stroke patients with acute completed ischaemic stroke: n = 1181; population based controls: n = 1569). None of the six SNPs showed significant association with ischaemic stroke in the whole stroke sample before and after adjustment for conventional stroke risk factors (age, sex, hypertension, diabetes, and hypercholesterolaemia). Haplotype analysis did also not reveal any significant association. Marginally positive statistical measures of association in the subgroup with cardioembolic stroke did not remain significant after correction for multiple testing. In conclusion, this study was unable to demonstrate an association between the six SNPs which had showed significant single marker association with stroke in the Icelandic stroke cohort and ischaemic stroke in a large German cohort.     

Two Novel SNPs in the PLCL2 Gene Associated with Large Artery Atherosclerotic Stroke Identified by Fine-Mapping

A genome-wide association study (GWAS) reported that the single nucleotide polymorphism (SNP) rs4618210 in the PLCL2 gene is related to myocardial infarction (MI) in the Japanese population, but no study has examined the correlation of PLCL2 with ischemic stroke (IS). The present study was designed to investigate whether the genetic variation in PLCL2 is associated with large artery atherosclerotic (LAA) stroke in a Han Chinese population. Tagging SNPs (tSNPs) of the PLCL2 gene were determined by a fine-mapping strategy and were genotyped by improved multiplex ligation detection reaction (iMLDR) technology in 669 LAA stroke patients and 668 healthy controls. A logistic regression model was used to analyze the associations between genetic variation at PLCL2 and the risk of LAA stroke. Two SNPs were significantly associated with the risk of LAA stroke after adjusting for potential confounders: for rs4685423, the AA genotype and CA genotype decreased the risk of LAA stroke compared with the CC genotype (multivariate-adjusted, P = 0.001); for rs4618210, the AA genotype and GA genotype decreased the risk of LAA stroke compared with the GG genotype (multivariate-adjusted, P = 0.007). In addition, haplotype analysis indicated that compared with haplotype TTT, haplotype TAT decreased the risk of LAA stroke in block 2 (adjusted OR, 0.706; 95% CI, 0.550–0.907; P = 0.006). The analysis of SNP–SNP interactions showed that rs4685423 was the most influential contributor to LAA stroke risk. SNPs rs4685423 and rs4618210 in the PLCL2 gene may be related to the risk of LAA stroke in Han Chinese.     

Inflammatory system gene polymorphism and the risk of stroke: a case-control study in an Indian population

Sequence variations in genes involved in inflammation system are known to contribute to the risk of cardiovascular diseases (CVD) including stroke. In this study, we performed a genetic association study on the single nucleotide polymorphisms (SNPs) present in the genes CD14 (-159 C/T), TNFalpha (-308 G/A), IL-1alpha (-889 C/T), IL-6 (-174 G/C), PSMA6 (-8 C/G), and PDE4D (SNP83 T/C, respectively) in order to discern their possible role in the susceptibility to stroke in a North Indian population. These SNPs were previously found to be associated with CVD through their contribution to inflammation. A case-control design was used to examine 176 stroke patients (112 ischemic and 64 hemorrhagic stroke patients) and 212 unrelated healthy control individuals. After adjustment for the confounding risk factors, the IL-1alpha -889 T allele carriers (TT+CT) were found to be strongly associated with both forms of stroke (OR=2.56; 95% CI=1.53-4.29; P=0.0004). The CC genotype of PDE4D was found to be associated only with ischemic stroke (OR=2.02; 95% CI=1.08-3.76; P=0.03). None of the variants tested for the CD14, TNFalpha, IL-6, and PSMA6 genes found to confer risk for stroke in the study population. In conclusion, the -889 C/T and SNP83 T/C SNPs of the IL-1alpha and PDE4D genes, respectively, appear to be genetic risk factors for stroke in our study population.     

Association between phosphodiesterase 4D gene and ischaemic stroke

Background

An association between the phosphodiesterase 4D (PDE4D) gene and risk of ischaemic stroke in an Icelandic population has been suggested by the deCODE group.

Methods

A case–control study of 151 hospitalised patients with first‐ever ischaemic stroke and 164 randomly selected age‐matched and sex‐matched community controls was conducted. PDE4D genotypes for the six single‐nucleotide polymorphisms (SNPs) previously reported to be independently associated with stroke were determined, common haplotypes were inferred using the expectation‐maximisation algorithm, and SNP and haplotype associations with stroke were examined. A meta‐analysis of published studies examining the association between PDE4D and stroke was also carried out.

Results

Our study of Australian patients with stroke showed an independent association between ischaemic stroke and PDE4D SNP 89 (CC: odds ratio (OR) 5.55, 95% confidence interval (CI) 1.02 to 30.19; CA: OR 1.68, 95% CI 0.96 to 2.96; AA: OR 1 (reference)), SNP 87 (CC: OR 2.13, 95% CI 1.08 to 4.20; TC: OR 1.64, 95% CI 0.89 to 3.00; TT: OR 1 (reference)) and SNP 83 (TT: OR 2.16, 95% CI 1.08 to 4.32; TC: OR 1.37, 95% CI 0.77 to 2.43; CC: OR 1 (reference)), and between ischaemic stroke and PDE4D haplotypes at SNP 89–87–83 (A–C–C: OR 2.13, 95% CI 1.15 to 3.96; C–C–T: OR 2.25, 95% CI 1.29 to 3.92), but no association between ischaemic stroke and PDE4D SNP 56, SNP 45 or SNP 41, or with PDE4D haplotypes at SNP 56–45–41. A meta‐analysis of nine case–control studies (including our current results) of 3808 stroke cases and 4377 controls confirmed a significant association between stroke and PDE SNP 87 (pooled p = 0.002), SNP 83 (0.003) and SNP 41 (0.003). However, there was statistical heterogeneity (p<0.1) among the studies in the direction of association for each of the individual SNPs tested.

Conclusions

Our results and the pooled analyses from all the studies indicate a strong association between PDE4D and ischaemic stroke. This strengthens the evidence that PDE4D plays a key part in the pathogenesis of ischaemic stroke. Heterogeneity among the studies in the direction of association between individual SNPs and stroke suggests that the SNPs tested are in linkage disequilibrium with the causal allele(s).Stroke is one of the leading causes of death and long‐term disability worldwide. About 80% of strokes are ischaemic in origin, most commonly caused by atherosclerosis.¹ By recognising and treating individuals and populations at risk, the burden of stroke can be reduced. As only about two thirds of ischaemic strokes seem to be attributable to known environmental risk factors,² there are likely to be other as yet unknown causal risk factors for ischaemic stroke.In recent years, there have been several reports of genetic polymorphisms that are associated with an increased (or decreased) risk of stroke.^3,4,5,6 In 2002, the deCODE group published the results of a genomewide screen for stroke susceptibility genes in Iceland.⁷ Among 260 phosphodiesterase 4D (PDE4D) single‐nucleotide polymorphisms (SNPs) examined, six were significantly associated with stroke after adjustment for multiple comparisons.To establish a causal association between the PDE4D gene and stroke, the results of the study by the deCODE group need to be validated externally in independent datasets. Recently published studies from different populations^{8,9,10,11,12,13,14,15} provide apparently conflicting evidence on the association between the PDE4D gene and stroke. We explored the relationship between PDE4D genotype and ischaemic stroke in a case–control study of consecutive Australian patients admitted to hospital with ischaemic stroke and a similar number of randomly selected community controls. We determined PDE4D genotypes among patients and controls for the six SNPs found by the deCODE group to be markedly associated with stroke (SNP 89, SNP 87, SNP 83, SNP 56, SNP 45 and SNP 41) and examined the association between these SNPs and PDE4D haplotypes and ischaemic stroke. We also carried out a meta‐analysis of published studies to explore the consistency of the association between PDE4D and stroke.     

磷酸二酯酶4D基因多态性与缺血性脑血管病的关系

目的 探讨中国汉族人群磷酸二酯酶4D (PDE4D) 基因多态性与缺血性脑血管病(ICVD)的关系.方法 采用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)方法检测116例ICVD患者和110名正常对照者PDE4D基因SNP45、SNP83和rs918592位点的多态性及其与糖代谢指标的关系.结果 PDE4D基因rs918592的A等位基因频率ICVD组(58.6%)、腔隙性脑梗死亚组(63.8%)较正常对照组(48.6%)明显增高(均P<0.05);rs918592、SNP83基因型及等位基因频率各组间差异无统计学意义(均P>0.05);SNP45位点未见多态性.糖代谢指标在不同的SNP83、rs918592 基因型间差异无统计学意义(均P>0.05).结论 中国汉族人群PDE4D基因rs918592位点上A等位基因可能是ICVD的危险因素之一; PDE4D基因可能不是通过糖代谢影响ICVD的发生.     

Association of phosphodiesterase 4D gene G0 haplotype and ischaemic stroke in a Greek population

We have examined the association of phosphodiesterase 4D ( PDE4D ) single nucleotide polymorphism (SNP45) and microsatellite marker AC008818-1 with ischaemic stroke, in an independent cohort of Greek patients and control individuals with no clinical manifestations of vascular disease. Significantly different distributions were observed with respect to the AC008818-1 alleles, with allele 148 associating with an increased risk of stroke incidence, and allele 144 with a protective effect. In addition, the haplotype defined by allele 148 and G allele of SNP45 was found to be significantly increased in patients even though no statistically significant differences emerged with respect to SNP45 alone. The previously established association of a PDE4D gene haplotype with ischaemic stroke in a population from Iceland was independently confirmed in our Greek population, suggesting that PDE4D may be involved in the aetiology and pathogenesis of stroke.     

ALOX5AP genetic variants and risk of atherothrombotic stroke in the Taiwanese population

We explored the role of variants of the arachidonate 5-lipoxygenase-activating protein (ALOX5AP) gene as factors for atherothrombotic stroke (ATS). A HapMap-based haplotype-tagging single nucleotide polymorphism (htSNP) association study was conducted in an isolated Taiwanese population. Multivariate logistic regression analyses revealed that patients with the GG/CG genotype of rs4293222 and the AA/AG genotype of rs4360791 had a 1.61-fold (odds ratio [OR]=1.61; 95% confidence interval [CI]=1.02-2.56, p=0.042) and a 1.69-fold (OR=1.69; 95% CI=1.00-2.86, p=0.047) increased risk of ATS, compared with patients with the CC/GG genotype, respectively. The most common haplotype allele, GTA, was used as a reference when analyzing the association between the haplotypes related to rs4293222, rs10507391, rs12429692 and ATS. The combined frequencies of all minor variant alleles of the three selected htSNP were associated with a 44% decreased risk of ATS (OR=0.56; 95% CI=0.37-0.84, p=0.005). This study provides preliminary evidence suggesting that genetic polymorphisms of ALOX5AP are associated with ATS.     

Genetics of ischaemic stroke

Ischaemic stroke is a heterogeneous multifactorial disorder. Epidemiological data provide substantial evidence for a genetic component to the disease, but the extent of predisposition is unknown. Large progress has been made in single-gene disorders associated with ischaemic stroke. The identification of NOTCH3 mutations in patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL) has led to new insights on lacunar stroke and small-vessel disease. Studies of sickle-cell disease have drawn attention to the importance of modifier genes and of gene-gene interactions in determining stroke risk. They have further highlighted a potential role of genetics in predicting stroke risk. Little is known about the genes associated with complex multifactorial stroke. There are probably many alleles with small effect sizes. Genetic-association studies on a wide range of candidate pathways, such as the haemostatic and inflammatory system, homocysteine metabolism, and the renin-angiotensin aldosterone system, suggest a weak but significant effect for several at-risk alleles. Genome-wide linkage studies in extended pedigrees from Iceland led to the identification of PDE4D and ALOX5AP. Specific haplotypes in these genes have been shown to confer risk for ischaemic stroke in the Icelandic population, but their role in other populations is unclear. Advances in high-throughput genotyping and biostatistics have enabled new study designs, including genome-wide association studies. Their application to ischaemic stroke requires the collaborative efforts of multiple centres. This approach will contribute to the identification of additional genes, novel pathways, and eventually novel therapeutic approaches to ischaemic stroke.     

ALOX5AP基因突变与缺血性脑卒中的关系

目的 探讨ALOX5AP基因突变与缺血性脑卒中的关系.方法 采用聚合酶链反应-单链构象多态性法及双脱氧末端终止法分析26例急性脑梗死患者及23名正常对照者的ALOX5AP基因的单核苷多态性(SNPs).结果 脑梗死组出现ALOX5AP基因SG13S100杂合型(A/G)(18例,69.2%)的频率显著高于正常对照组(8人,34.8%)(P＜0.05).男性脑梗死患者ALOX5AP基因SG13S100杂合型(A/G)的频率(86.7%)明显高于女性患者(45.5%)(P＜0.05).结论 ALOX5AP基因突变与缺血性脑卒中的发生有关, 急性脑梗死患者ALOX5AP基因SG13S100的突变率显著增高,其中男性患者尤为明显.     

Increased Left Atrial Appendage Density on Computerized Tomography is Associated with Cardioembolic Stroke

Background and purpose: While studies have stratified cardioembolic (CE) stroke risk by qualitative left atrial appendage (LAA) morphology and biomarkers of atrial dysfunction, the quantitative properties that underlie these observations are not well established. Accordingly, we hypothesized that LAA volume and contrast density (attenuation) on computerized tomography (CT) may capture the structural and hemodynamic processes that underlie CE stroke risk. Methods: Data were collected from a single center prospective ischemic stroke database over 18 months and included all patients with ischemic stroke who previously underwent routine, nongated, contrast enhanced thin-slice (≤2.5 mm) chest CT. Stroke subtype was determined based on the inpatient diagnostic evaluation. LAA volume and attenuation were determined from CT studies performed for various clinically appropriate indications. Univariate and multivariable analyses were performed to determine factors associated with ischemic stroke subtype, including known risk factors and biomarkers, as well as LAA density and morphologic measures. Results: We identified 311 patients with a qualifying chest CT (119 CE subtype, 109 Embolic Stroke of Undetermined Source (ESUS), and 83 non-CE). In unadjusted models, there was an association between CE (versus non-CE) stroke subtype and LAA volume (OR per mL increase 1.15, 95% CI 1.07-1.24, P < .001) and LAA density (4th quartile versus 1st quartile; OR 2.95, 95% CI 1.28-6.80, P = .011), but not with ESUS (versus non-CE) subtype. In adjusted models, only the association between LAA density and CE stroke subtype persisted (adjusted OR 3.71, 95% CI 1.37-10.08, P = .010). Conclusion: The LAA volume and density values on chest CT are associated with CE stroke subtype but not ESUS subtype. Patients with ESUS and increased LAA volume or attenuation may be a subgroup where the mechanism is CE and anticoagulation can be tested for secondary stroke prevention.     

Meta-analysis of association between variation in the PDE4D gene and ischemic cerebral infarction risk in Asian populations

Phosphodiesterase 4D (PDE4D) was found to be associated with increased risk of ischemic stroke by Iceland researchers in 2003. Replication studies have produced conflicting results. A recent meta-analysis reported that no genetic variant of PDE4D demonstrated a reproducible association with ischemic stroke, especially when analyzed with respect to white subjects exclusively. In this study, we aimed to determine the association between PDE4D and ischemic infarction risk in Asian populations. After collecting all case–control studies in English or Chinese related to the association between PDE4D and ischemic infarction in Asian people, strict selection criteria and exclusion criteria were determined, and a fixed or random effects model was used on the basis of heterogeneity. To measure the strength of the genetic association, a pooled odds ratio (OR) and 95% confidence interval (CI) were calculated for each gene variant. Publication bias was evaluated. None of the Asian subjects were heterozygous for SNP 45 or SNP 41. Only seven studies involving SNP 83 and SNP 87 had sufficient data to allow inclusion into meta-analyses. Statistically significant associations with ischemic infarction in the Asian populations were determined for SNP 83 C allele (OR, 1.22; 95% CI, 1.03–1.43) and SNP 83 CC genotype (OR, 1.42; 95% CI, 1.14–1.77), but not for SNP 83 CC + CT genotypes or SNP 87. PDE4D was associated with ischemic infarction risk in Asian people, and SNP 83 was an important biomarker.     

Cyclin-dependent kinase 5 is associated with risk for Alzheimer’s disease in a Dutch population-based study

Although the role of the Cdk5 protein in Alzheimer's disease (AD) is well recognized, there have been relatively few studies investigating genetic variants in the CDK5 gene in AD. In this study, we assessed the association between five previously described single nucleotide polymorphisms (SNPs) in the CDK5 gene and late onset AD by means of logistic regression and haplotype association analyses. Including all prevalent and incident AD cases, we found a significantly increased risk of AD for carriers of the GG genotype of SNP rs2069442 (OR = 1.79, 95 % CI 1.16-2.79, p = 0.001) in those without APOE*4. When limiting the analysis to incident cases without APOE*4, carriers of the GG genotype showed a 1.9-fold increased risk of AD (95 % CI 1.16-3.10, p = 0.003). Variations in the CDK5 gene can be described in 5 haplotype blocks. In our analysis, the haplotype tagged by the G allele of SNP rs2069442 was significantly associated with AD (p = 0.05). In conclusion, our study suggests that CDK5 may be associated with AD.     

An extended 5'-tau susceptibility haplotype in progressive supranuclear palsy

OBJECTIVE: To confirm the association of an extended 5'-tau haplotype on chromosome 17q with the disease phenotype in clinically ascertained individuals with sporadic progressive supranuclear palsy (PSP). BACKGROUND: PSP is a neurodegenerative disease with parkinsonian signs accompanied by vertical supranuclear palsy and tau pathologic features. Previously, we documented the complete segregation of an extended 5'-tau haplotype consisting of four single nucleotide polymorphisms (SNP) with the disease phenotype in sporadic PSP. This study was conducted in an independent cohort to confirm these results and to improve the statistical power of the data. DESIGN AND METHODS: Direct sequencing and restriction enzyme digests were used to analyze four SNP in tau Exons 1, 4A, and 8. These contiguous SNP were used to reconstruct an extended 5'-tau haplotype in 52 affected and 54 age-matched control individuals. RESULTS: The four SNP formed two homozygous 5'-tau haplotypes (HapA and HapC) or a heterozygous genotype. Fifty-one (98%) patients with PSP had HapA; one (2%) with a later onset was heterozygous; and none had HapC. These PSP haplotype frequencies were different (p < 0.00001) from those of the age-matched control group, in which 18 (33%) people had HapA; 26 (48%) were heterozygous; and 10 (19%) had HapC. The extended 5'-tau haplotype, HapA, had a high sensitivity (98%) and a moderate specificity (67%) as a marker for PSP. CONCLUSIONS: A 5'-tau susceptibility haplotype may be a sensitive marker for sporadic PSP and a genetic defect in, or closely linked to, tau may contribute to the cause of PSP.     

Novel, replicated associations between dopamine D3 receptor gene polymorphisms and schizophrenia in two independent samples.

BACKGROUND: Meta-analyses have suggested an association between schizophrenia (SZ) and a coding polymorphism (rs6280/Ser9Gly) at the dopamine D3 receptor gene (DRD3), but results have been inconsistent. Because most studies have evaluated only rs6280, the inconsistencies might reflect associations with other variants. METHODS: We analyzed polymorphisms spanning 109kb in two independent samples (United States: 13 single nucleotide polymorphisms (SNPs), 331 cases, 151 trios, 274 control subjects; India: 11 SNPs, 141 trios). RESULTS: In the U.S. samples, significant associations were detected with eight SNPs, including rs6280 (p = .001, odds ratio: 1.5). Consistent associations in the case-control and family-based analyses were detected with a common haplotype spanning intron 1 to the 3' region of the gene (rs324029-rs7625282-rs324030-rs2134655-rs10934254; case-control, p = .002; transmission disequilibrium test [TDT], p = .0009; global p-values = .002 and .007, respectively). In the Indian sample, one SNP was associated (rs10934254, p = .03). Moreover, over-transmission of the same common haplotype as the U.S. sample was observed in this cohort (TDT, p = .005; global test, p = .009). Ser9Gly (rs6280) was associated with SZ against this haplotype background but not other haplotypes. CONCLUSIONS: These data suggest previous inconsistencies might have resulted from associations with other DRD3 variants. A liability locus might be in linkage disequilibrium (LD) with or carried against, an associated haplotype 3' to rs6280. Comprehensive SNP evaluation in larger samples is needed.