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PubMed1998

Analysis and meta-analysis of two serotonin transporter gene polymorphisms in bipolar and unipolar affective disorders.

The serotonin transporter is a compelling candidate gene to examine in bipolar and unipolar affective disorder, since drugs that specifically inhibit the serotonin transporter can successfully treat depression. Previous association studies of a VNTR polymorphism in intron 2 and a functional insertion/deletion polymorphism in the promoter of this gene have produced conflicting results. The present study examined allele and genotype frequencies for both of these polymorphisms and resulting haplotypes in 87 English Caucasian bipolar patients, 125 English Caucasian unipolar affective disorder patients, and 174 controls. No significant associations were detected when these unipolar or bipolar cases were compared either separately or as a pooled "affective disorder" group to the controls. A meta-analysis of over 1,400 individuals of European Caucasian origin was then performed, comprising 772 controls, 375 bipolar and 299 unipolar patients for the VNTR polymorphism, and 739 controls, 392 bipolar and 275 unipolar patients for the promoter polymorphism. A significant association of promoter allele 2 was shown with bipolar (estimated odds ratio 1.21; 95% confidence interval 1.00-1.45), unipolar (OR 1.23; 95% CI 1.01-1.42), and combined bipolar + unipolar groups (OR 1.22; 95% CI 1.04-1.42). There was no demonstrable allelic association of the VNTR polymorphism with affective disorder: for the combined bipolar + unipolar group the odds ratios for VNTR alleles 9 and 10, compared with the common allele 12 were 1.05 (95% CI 0.56-1.95) and 0.90 (95% CI 0.77-1.05). These results suggest that the promoter allele 2, which has previously been shown to result in lower levels of serotonin transporter transcription, may be associated with affective disorder risk.

Adult↗
PubMed1998

Clinical value of soluble IgG Fc receptor type III in plasma from patients with chronic idiopathic neutropenia.

Previous studies have shown that the plasma level of soluble IgG Fc receptor type III (sFcgammaRIII) is a measure of the total body neutrophil mass. The aim of this study was to determine whether the plasma level sFcgammaRIII is associated with the risk of contracting bacterial infections in patients with neutropenia. We collected blood from 66 patients suffering from acquired idiopathic neutropenia, whose blood was sent to our laboratory for diagnostic evaluation of neutropenia (neutrophil count <1,500 cells/microL). Soluble FcgammaRIII levels were measured in plasma. Genotype distibutions of FcgammaR polymorphisms were determined. Clinical data were obtained from the patient files. Patients were assessed as to whether or not they had suffered from a bacterial infection 3 months before to 3 months after a single sFcgammaRIII measurement. In addition, longitudinal data were obtained from 21 patients. Of the 66 neutropenic patients who were included, 15 had suffered from a bacterial infection in the period 3 months before to 3 months after sFcgammaRIII measurement. The age and sex distribution was equal among the groups with and without infections, as were the genotype frequencies of neutrophil FcgammaR polymorphisms. Both neutrophil count and plasma level sFcgammaRIII were significantly lower in the patient group with infections, compared with the noninfected group (P = .03 and P < .0001, respectively). No infections were reported for patients who had plasma sFcgammaRIII levels above 100 arbitrary units (AU; normal value, 30 to 200). After matching each infected patient with two noninfected patients having the same neutrophil count, sFcgammaRIII plasma levels remained significantly lower in the group with infections (P = . 0001). For the patients who were followed in time, no infections were reported when sFcgammaRIII levels were above 100 AU. In conclusion, our population of patients with chronic idiopathic neutropenia with plasma sFcgammaRIII levels above 100 AU did not show an increased risk of contracting bacterial infections.

Adolescent↗
PubMed1998

Detection of the two short tandem repeat loci (HumTPO and HumLPL) in Japanese populations using discontinuous polyacrylamide gel electrophoresis.

Two short tandem repeat (STR) systems, HumTPO and HumLPL, were investigated in 218 unrelated Japanese living in Gunma and Fukui Prefectures by means of discontinuous, horizontal polyacrylamide gel electrophoresis and silver staining. Five and six alleles were identified at the HumTPO and HumLPL loci, respectively. No deviations from the Hardy-Weinberg equilibrium or differences in genotype frequency were found between the two Japanese populations in the two systems. Our detection methods offered several advantages including time-saving and safe electrophoretic procedures, and fast and easy silver-staining, in comparison with standard and conventional STR analysis using vertical polyacrylamide gel electrophoresis.

Electrophoresis, Polyacrylamide Gel↗
PubMed2004

Association of male infertility with Pro185Ala polymorphism in the aryl hydrocarbon receptor repressor gene: implication for the susceptibility to dioxins.

OBJECTIVE: To examine whether Arg554Lys polymorphism in the gene for aryl hydrocarbon receptor (AHR) and/or Pro185Ala polymorphism in the gene for aryl hydrocarbon receptor repressor (AHRR) constitutes a susceptibility locus for dioxin-related male infertility. DESIGN: Association study of male infertility with polymorphisms. SETTING: National research institute and university hospitals. PATIENT(S): 123 Japanese men with azoospermia or severe oligozoospermia and 112 men with proven fertility. INTERVENTION(S): Polymorphism analysis. MAIN OUTCOME MEASURE(S): The allele and genotype frequencies between infertile men and controls. RESULT(S): The allele and genotype frequencies of the AHR polymorphism were comparable between infertile men and controls. By contrast, although the difference in the allele frequency of the AHRR polymorphism did not reach a significant level, the genotype frequency was statistically significantly different between the two groups of men. Furthermore, the statistical difference became more significant when the frequency was compared between the Pro/Pro genotype and the Pro/Ala plus Ala/Ala genotype. CONCLUSION(S): The Pro185Ala polymorphism in AHRR may constitute a susceptibility locus for dioxin-related male infertility. It appears that the negative feedback effect of AHRR on dioxin-related signaling is weaker for the proline allele than for the alanine allele, and that the hypomorphic function of the proline allele exerts a recessive adverse effect on male fertility.

Adult↗
PubMed1997

Analysis of the apo E/apo C-I, angiotensin converting enzyme and methylenetetrahydrofolate reductase genes as candidates affecting human longevity.

Genetic factors are likely to affect human survival, since twin studies have shown greater concordance for age of death in monozygotic compared to dizygotic twins. Coronary artery disease is an important contributor to premature mortality in the UK. Accordingly, we have chosen genes associated with cardiovascular risk, apo E/apo C-I, angiotensin converting enzyme (ACE) and methylenetetrahydrofolate reductase (MTHFR), as candidates which may affect longevity/survival into old age. An association study was performed by comparing allele and genotype frequencies at polymorphic loci associated with these genes in 182 women and 100 men aged 84 years and older with 100 boys and 100 girls younger than 17 years. MTHFR allele and genotype frequencies were similar in the elderly and young populations. Apo C-I allele and genotype frequencies were significantly different in the elderly women compared to the younger sample (P < 0.05). No difference was observed in the elderly men. At the neighbouring apo E gene, we only observed a difference between genotypes in the elderly women and the young sample; however, this did not retain significance when the genotype frequencies of the young sample were adjusted to values expected from the allele frequencies on the basis of Hardy-Weinberg equilibrium and compared to observed genotypes in elderly men and women. In contrast to previous studies, apo E2 was not overrepresented in the elderly men or women. Thus, the proposition that apo E2, E3 and E4 protein isoforms are themselves functionally associated with increasing risks for early death, may be too simplistic. The I/I ACE was depleted in the elderly males but not the elderly females. Furthermore, significant differences were observed between ACE genotypes in elderly men and elderly women. These data suggest that the penetrance of loci which influence survival may vary according to sex. The depletion of the ACE I/I genotype in elderly men is generally consistent with a previous study which found decreased frequencies of the I allele in French centenarians compared to younger controls. However, these results are apparently paradoxical, since others have suggested that the I allele is associated with increased cardiovascular risk. Clarification of the overall effect of a genotype on survival will be vital if therapies are to be considered which target specific genetic variants.

Adolescent↗
PubMed2003

Genotyping of cytochrome p450 isoform genes is useful for forensic identification of cadaver.

Tailor-made medical treatment based on the polymorphism of genes encoding drug-metabolizing enzymes has been advocated and is being tried on an experimental basis at numerous centers. If DNA polymorphism analysis becomes routine in tailor-made medical treatment, it will be very useful in forensic identification. In this study, we determined the genotype frequencies of five p450 (CYP) isoform genes, CYP1A2, CYP2D6, CYP2E1, CYP2C9 and CYP2C19 in 196 Japanese individuals to evaluate their forensic usefulness. These genes encode the most important enzymes among the CYP superfamily that metabolize clinically used drug. The frequency of each allele agreed well with those reported previously and their genotype frequencies did not deviate from those expected from Hardy-Weinberg equilibrium. CYP2C subfamilies such as CYP2C9 and CYP2C19 on chromosome 10 showed high sequence homology, as high as over 95% in the regions flanking polymorphic sites. Although 3240 genotype combinations of these five CYP isoform genes are theoretically possible, 101 combinations were detected in this study. The genotype frequencies of these five isoform genes excluded their linkage. The following two genotype combinations showed the highest frequency of 0.036: CYP1A2*1A/*1A, CYP2D6*1/*10, CYP2E1*1/*1, CYP2C9*1/*1 and CYP2C19*1/*1 and CYP1A2*1A/*1C, CYP2D6*1/*10, CYP2E1*1/*1, CYP2C9*1/*1 and CYP2C19*1/*1. Thus, genotyping of CYP isoform genes should be useful in forensic identification.

Alleles↗
PubMed2000

A novel PCR-based method for direct Fc gamma receptor IIIa (CD16) allotyping.

Leukocyte IgG receptors (Fc gamma R) are important immune-response modulating molecules. Fc gamma RIIIa is expressed on macrophages, NK-cells and gamma delta-T cells and exhibits a genetically determined, functional polymorphism at nucleotide 559. This allelic difference predicts either a phenylalanine (F158) or valine (V158) at amino acid 158 in the membrane-proximal extracellular domain, and has been shown to be associated with autoimmune and infectious diseases. Published methods to determine Fc gamma RIIIa genotypes are cumbersome. Therefore, we developed a novel, rapid and reliable PCR-based method to determine Fc gamma RIIIa genotypes. Comparison of genotyping results with direct Fc gamma RIIIa sequencing of 60 blood donors showed 100% accuracy of this new method. Since genotype frequencies of Fc gamma R polymorphisms depend strongly on race and ethnicity, we compared Fc gamma RIIIa genotype frequencies of 176 Caucasian Dutch and 104 Japanese blood donors. Interestingly, these frequencies were not significantly different (P>0.1), in contrast to the Fc gamma RIIa and Fc gamma RIIIb genotype frequencies (P<0.001).

Alleles↗
PubMed2005

Is tissue-plasminogen activator gene polymorphism a risk factor for venous thromboembolism in every population?

BACKGROUND: Tissue-plasminogen activator is a key protein of fibrinolytic system. In recent years the relation between t-PA, its genetic polymorphisms and arterial or venous thrombosis were investigated in different populations. The aim of this study is to investigate the role of t-PA gene polymorphism in Turkish venous thromboembolism (VTE) patients. METHODS: A case-control study was performed. We investigated the t-PA insertion/deletion (I/D) polymorphism in 93 VTE patients and 146 controls without VTE. Recurrent cases and documented risk factors for PTE were recorded. RESULTS: Cases and controls did not differ with respect to the different t-PA genotypes. The prevalence of I allele was 44.1%, 44.5% in cases and controls respectively (OR = 0.95, 95% CI: 0.78-1.24, p > 0.05). Different t-PA genotypes had no effect on recurrent disease. No gender difference was observed with respect to the different t-PA genotypes. There was no significant difference for genotype frequency between PTE patients with documented risk factors and unprovoked cases. CONCLUSIONS: In conclusion there was no association between t-PA genotype and VTE in this group of Turkish population. It was also found that genotype frequencies for t-PA in both VTE and control subjects seems different from those reported from western part of the world. ABBREVIATED ABSTRACT: The aim of this study is to investigate the role of t-PA gene polymorphism in Turkish VTE patients. We investigated 93 VTE patients and 146 controls without VTE. Cases and controls did not differ with respect to the different t-PA genotypes. The prevalence of I allele was 44.1%, 44.5% in cases and controls respectively (OR = 0.95, 95% CI: 0.78-1.24, p > 0.05). Different t-PA genotypes had no effect on recurrent disease. No gender difference was observed with respect to the different t-PA genotypes. There was no significant difference for genotype frequency between PTE patients with documented risk factors and unprovoked cases. In conclusion there was no association between t-PA genotype and VTE in this group of Turkish population. It was also found that genotype frequencies for t-PA in both VTE and control subjects seems different from those reported from western part of the world.

Base Sequence↗
PubMed1996

VNTR locus D1S80: allele frequencies and genotype distribution in the region of Düsseldorf.

Hypervariable loci within the human genome are useful tools in several disciplines: for example in forensic medicine (paternity testing and forensic identification). One of these genetical markers is located at chromosome 1 and is called D1S80 (MCT118). The genotype distribution and the allele frequency of the VNTR locus D1S80 have been studied in a population of 378 unrelated Germans living at Düsseldorf. The determination of genotypes has been carried out by using the polymerase chain reaction and subsequent analysis of the amplified products by polyacrylamide electrophoresis followed by silver staining. The data demonstrate that the locus is highly polymorphic with an observed heterozygosity of 75.66%. The frequency distribution found does not meet Hardy-Weinberg expectations. We think that this is not astonishing because we found only 80 of the possible 231 phenotypes (alleles 16-34, 36-37, without anodal and cathodal variants). So before using the D1S80 data in forensic analyses and paternity tests a larger data base has to be established. The data of the Düsseldorf sample are compared with data of studies on other populations.

Alleles↗
PubMed2000

[Genetic polymorphisms of Rb and susceptibility of esophageal cancer].

OBJECTIVE: To assess the possible association between the polymorphisms of Rb (intron 20, 17) and susceptibility of esophageal cancer so as to provide clues for genetic markers of esophageal cancer. METHODS: Samples were taken from 56 normal Han people of Shaanxi, 47 esophageal cancer samples, and 31 peri-cancerous non-tumor. DNAs were analysed by using PCR technique. RESULTS: Ten alleles fragments were found in Han population of Shannxi by using primer Rb gene (intron 20). PIC was 0.86. Heterozygosity was 0.7. In esophageal cancer tissues, PIC was 0.82. Heterozygosity was 0.55. In peri-cancerous non-tumor, PIC was 0.87. Heterozygosity was 0.74. Distribution of genotype frequency was significantly different between Han population of Shaanxi and esophageal cancer (P < 0.01). Two alleles (945 bp, 630 bp + 315 bp) fragments were found in Han population of Shaanxi by using primer Rb gene (intron 17). Genotype frequency of Han population of Shaanxi was A/A: 0.28, A/B: 0.52, B/B: 0.20. Genotype frequency of esophageal cancer was A/A: 0.11, A/B: 0.77, B/B: 0.12. Distribution of genotype frequency was significantly different between Han population of Shaanxi and esophageal cancer (P < 0.05). Mutation of Rb gene was found in 7 cases. CONCLUSIONS: Polymorphism of Rb (intron 20) VNTR and Rb (intron 17) could be used as valuable markers. There should bea relationship between polymorphism of Rb VNTR and esophageal cancer susceptibility.

Esophageal Neoplasms↗
PubMed2004

[The study on HLA-Cw polymorphism from Xi'an Han population by PCR-sequence specific oligonucleotide probe].

OBJECTIVE: To determine the HLA-Cw allele and genotype frequencies from Xi'an Han population and obtain genetic data. METHODS: The results of HLA-Cw typing for 130 randomly selected from Xi'an Han population were obtained by using the PCR-Sequence Specific Oligonucleotide Probes (SSOP). RESULTS: In this investigation, 16 alleles were detected among 130 unrelated individuals with frequencies from 0.0077 to 0.1588 and HLA-Cw*01,03,07 were the most common HLA-Cw alleles. We have made a survey of HLA-Cw alleles frequencies in Xi'an Han Population, with blank frequency being lowered to 0.018 2. CONCLUSION: The distribution of genotype frequencies met the law of Hardy-Weinberg equilibrium by Hi-square test. The frequency data can be used in forensic and paternity tests, transplant matching and anthropology.

Alleles↗
PubMed2004

Association of the dopamine transporter gene (DAT1) core promoter polymorphism -67T variant with schizophrenia.

Dysfunction of the central dopaminergic neurotransmission has been suggested to play an important role in the etiology of schizophrenia. The dopamine transporter (DAT1) mediates the active reuptake of dopamine from the synapses and thereby plays a key role in the regulation of the dopaminergic neurotransmission. In this study, we sought to determine the possible association of the DAT1 gene core promoter polymorphism -67A/T with schizophrenia in a case/control study. The allele and genotype frequencies of the polymorphism were studied in 100 patients and 100 controls, which were matched on the basis of sex, age, and ethnicity. The genotype frequencies in the patients group were as follows: AA 29%; AT 59%; TT 12% versus the genotype frequencies in the control group: AA 57%; AT 38%; TT 5% [chi2 = 16.54, df = 2, OR = 2.25 (95% CI 1.46-3.45, P < or = 0.0003]. For the first time, these findings provide tentative evidence for the contribution of the DAT1 gene core promoter polymorphism to the etiopathophysiology of schizophrenia at least in the Iranian male population that we studied. Replication studies of independent samples and family-based association studies are necessary to further evaluate the significance of our findings.

Adult↗
PubMed2005

[Distribution of apoE polymorphism in Chinese Yunnan Dehong Dai ethnic group].

OBJECTIVE: To investigate the distribution of apolipoprotein E (apo E) polymorphism in Chinese Dehong Dai and Kunming Han ethnic groups. METHODS: After the process of extracting genomic DNA from 171 Chinese Dehong Dai and 71 Chinese Kunming Han subjects, the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique was used to amplify the fourth exon of apoE, which contains site 112 and 158 in amino acid sequence, and the apoE polymorphism was detected. RESULTS: The genotyping frequencies of apolipoproteinE epsilon 2/2, epsilon 2/3, epsilon 2/4, epsilon3/3, epsilon3/4, epsilon4/4 in Dehong Dai were 0.006, 0.111, 0.006, 0.789, 0.088 and 0.000 respectively, while the genotyping frequencies of apoE epsilon2/2, epsilon2/3, epsilon2/4, epsilon3/3, epsilon3/4, epsilon4/4 in Kunming Han were 0.000, 0.169, 0.014, 0.718, 0.099, 0.000, respectively (P>0.05). The allelic frequencies of apoE epsilon2, epsilon3 and4 in Dehong Dai were 0.064, 0.889, 0.047 respectively, while the allelic frequencies of apoE epsilon2, epsilon3 and epsilon4 in Kunming Han were 0.092, 0.852, 0.056, respectively (P>0.05). CONCLUSION: The results revealed that either the frequency of genotype or that of allele of apoE gene polymorphism showed statistical difference between the ethnic populations. Compared with the data from other nationalities in China, the frequency of epsilon2 allele in Dehong Dai was significantly lower than that in Zhuang nationality (P<0.01); the frequency of epsilon3 allele in Dehong Dai was significantly higher than that in Chaoxian, Hui, Mongolian,Zhuang nationalities (P<0.05) and Uygur nationality (P<0.01); the frequency of epsilon4 allele in Dehong Dai was significantly lower than that in Olunchun nationality (P<0.05) and Uygur, Owenk nationalities (P<0.01). By comparison with the data from the populations of other races, the distribution of apoE gene polymorphism in Dehong Dai population is similar to that in Japanese population (P>0.05), but different from those in Singapore,European and American populations.

Adult↗
PubMed2005

[The C46359T polymorphism of DNMT3B promoter gene and pathogenesis of acute leukemia].

OBJECTIVE: To explore the relationship between the polymorphism of C46359T in DNMT3B promoter and the pathogenesis of acute leukemia (AL). METHODS: PCR-RFLP and DNA sequencing were used to analyze the genotypic polymorphism C46359T of promoter in genomic DNA of bone marrow cells/blood lymphocytes from 160 patients with AL and 240 normal controls. RESULTS: In people of the Hans in China, genotypic frequencies of 2.5% (CT), 97.5% (TT) and 0 (CC) were statistically significant (P < 0.001) comparing with the genotype frequencies of 41.8% (CT), 23.2% (TT) and 35.0% (CC) in Caucasian in USA. The genotypic frequency of CT heterozygote in 160 AL patients was 10.6%, significantly higher than that in the control subjects (2.5%, P < 0.001), indicating that the CT heterozygote might be a more frequent phenomenon in AL. Compared with TT homozygote, CT heterozygote had a 4.669-fold increased risk of acute leukemia (OR = 4.669; 95% confidence interval 1.700-14.747). It was suggested that CT heterozygote was relative to the pathogenesis of AL. CONCLUSIONS: Different distribution of genotypes in different races, the CT heterozygote was relative to the pathogenesis of AL.

Acute Disease↗
PubMed2002

Relationship between the platelet activating factor acetylhydrolase gene and intractability of ulcerative colitis.

PURPOSE: Platelet activating factor, which is a potent mediator of inflammatory injury in ulcerative colitis, is inactivated by platelet activating factor acetylhydrolase. Recently, a point mutation (G994 to T transversion) was observed in exon 9 of the platelet activating factor acetylhydrolase gene, and this mutation was found to be associated with a decrease in platelet activating factor acetylhydrolase activity in plasma. The aim of this study was to determine whether the gene mutation was associated with the severity of ulcerative colitis. METHODS: We studied 53 patients with ulcerative colitis and 108 control subjects. The plasma platelet activating factor acetylhydrolase genotype was determined as representative cases with three different genotypes (GG, GT, and TT) by an allele-specific polymerase chain reaction. RESULTS: There was no significant difference in genotypic frequency (GG, GT, and TT genotype frequencies were 68, 30, and 2 percent in controls and 55, 45, and 0 percent in ulcerative colitis patients). Platelet activating factor acetylhydrolase activity in plasma was also measured and did not differ significantly between ulcerative colitis patients and controls (1.50+/-0.12 vs. 1.81+/-0.34 nmol/min/50 microl, P = 0.60). However, according to the relationship between the platelet activating factor acetylhydrolase gene mutation and clinical characteristics of ulcerative colitis patients, the operative ratio cause of unresponsiveness to steroid therapy was significantly higher in patients with the GT genotype than in those with the GG genotype (66.7 vs. 27.6 percent, P = 0.019). CONCLUSION: We conclude that steroid-nonresponsive ulcerative colitis patients have a high frequency of the platelet activating factor acetylhydrolase gene mutation. Therefore, genotyping of this gene may be a useful marker to predict responsiveness to steroid therapy.

Adult↗
PubMed1997

Association of angiotensin-converting enzyme gene insertion/deletion polymorphism with the clinico-pathological manifestations in immunoglobulin A nephropathy patients.

OBJECTIVE: To investigate the relationship between angiotensin-converting enzyme (ACE) gene insertion/deletion polymorphism and the clinico-pathological manifestations in patients with immunoglobulin nephropathy (IgAN). METHODS: A flanking primer pair and an insertion-specific primer pair were used to perform two polymerase chain reactions so as to analyse the insertion/deletion polymorphism of ACE gene. RESULTS: There was a significantly higher genotype frequency for DD genotype in IgAN patients. The frequencies for DD genotype were also higher in those patients with hypertension and/or heavy proteinuria and/or severe glomerular sclerosis (P < 0.05). CONCLUSIONS: We observed a significant association of the deletion polymorphism of ACE gene with renal insufficiency, hypertension and severe glomerular lesions at biopsy. The deletion allele may play a role, at least to some extent, in the deterioration and progression in IgA nephropathy.

Adolescent↗
PubMed2005

Association of the serotonin transporter promoter polymorphism with smoking behavior among adolescents.

Serotonin transporter promoter polymorphism (5-HTTLPR) genotype was previously found associated with smoking behavior, difficulty in quitting smoking, and nicotine addiction; with non-replicated findings and contrasting results. Aim of the present study was to evaluate the possible association between 5-HTTLPR genotype and smoking behavior among adolescents, in relationship with psychological characteristics. Two hundred and ten Caucasian high school students (aged 14-19 years); 103 non-smokers, who have never smoked nicotine; and 107 tobacco smokers have been genotyped. Aggressiveness levels and temperamental traits were measured in both smokers and non-smokers, respectively, utilizing Buss-Durkee Hostility Inventory (BDHI) and Cloninger Three-Dimensional Personality Questionnaire (TPQ). Data about school performance have been also collected. The short-short (SS) genotype frequency was significantly higher among smokers compared with non-smokers (P = 0.023). The odds ratio for the SS genotype versus the long-long (LL) genotype frequency was 1.17 [95% CL (0.30-2.05)], when smokers were compared with non-smokers. The SS genotype frequency was significantly higher among heavy smokers with early onset, compared with moderate smokers with late onset (P = 0.042). BDHI irritability scores, NS scores at TPQ, and school failure frequency were significantly higher in smokers than in non-smokers. Multivariate model-fitting analysis evidenced a significantly greater relationship of genotype with irritability levels (BDHI scores) (0.34, P < 0.001) and temperament traits (NS scores) (0.36, P < 0.001), than with school performance (rate of school under-achievements) (0.18, P < 0.05) and nicotine smoking (number of cigarettes) (0.24, P < 0.01). Accordingly, factor-analysis showed that gene polymorphism contributes more directly to BDHI scores and NS scores (0.73; 0.71) than to smoking behavior and school under-achievement (0.54; 0.51). Our data suggest that a decreased expression of the gene encoding the 5-HTT transporter, due to "S" promoter polymorphism, may be associated with smoking behavior among adolescents and increased risk to develop nicotine dependence, possibly in relationship to personality traits, temperamental characteristics, and school under-achievements.

Achievement↗
PubMed1999

Angiotensin converting enzyme and endothelial nitric oxide synthase DNA polymorphisms and late onset Alzheimer's disease.

OBJECTIVES: Several lines of evidence suggest that the endothelial constitutive nitric oxide synthase (ecNOS) and angiotensin converting enzyme (ACE) may have a role in Alzheimer's disease. ACE is widely expressed in the brain, and a DNA polymorphism at the ACE gene has been linked to the risk for late onset Alzheimer's disease. Nitric oxide (NO) production by microglial cells, astrocytes, and brain microvessels is enhanced in patients with Alzheimer's disease. There is a growing evidence that NO is involved in neuronal death in Alzheimer's disease, and the oxidative stress caused by NO in the brain could be a pathogenic mechanism in Alzheimer's disease. The objective was to determine if two DNA polymorphisms at the ecNOS and ACE genes that have been linked with different levels of enzyme expression, have some effect on the risk of developing late onset Alzheimer disease. METHODS: A total of 400 healthy controls younger than 65 years and 350 patients with Alzheimer's disease (average age 72 years) were genotyped for the ACE and ecNOS polymorphisms. To define a possible role for these polymorphisms in longevity 117 healthy controls older than 85 years were also analysed. Genomic DNA was obtained and amplified by polymerase chain reaction, and genotypes were defined following a previously described procedure. Gene and genotype frequencies between patients and controls were compared statistically. RESULTS: Gene and genotype frequencies for the ecNOS and ACE polymorphisms did not differ between both groups of healthy controls (<65 years and >85 years). EcNOS gene and genotype frequencies were similar between patients and controls. There was a slight but significantly increased frequency of the ACE-I allele among patients with Alzheimer's disease compared with controls (p=0.03; OR=1.28, 95%CI= 1.04;1.58). CONCLUSIONS: The ACE-I allele was associated with a slightly increased risk of developing late onset Alzheimer's disease.

Age Factors↗