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VNTR Polymorphism (vntr + polymorphism)

Distribution by Scientific Domains

Medical Sciences	80%
Life Sciences	13%

Selected Abstracts

Dopamine transporter gene (DAT1) VNTR polymorphism in major psychiatric disorders: family-based association study in the Bulgarian population

ACTA PSYCHIATRICA SCANDINAVICA, Issue 5 2002
L. Georgieva
Objective:,A 40-bp variable number tandem repeat in the 3,-UTR of dopamine transporter gene (DAT1) has been examined for association with major psychiatric disorders in several case,control studies. No significant results have been found. We used a new collection of parent,offspring trios to test for association with schizophrenia (SZ), bipolar 1 disorder (BPI) and schizoaffective (SA) disorder. Method:,We genotyped trios from Bulgarian origin where the proband had SZ (178 trios), BPI (77 trios) and SA (29 trios). Alleles ranging from 5 to 11 repeats were observed. The results were analysed with the extended TDT (ETDT). Results:,No preferential transmission of alleles was observed for any diagnostic group. The presence of allele DAT*10 was associated with the severity and frequency of auditory hallucinations, however, this result is not significant if corrected for multiple testing. Conclusion:,Our results are in agreement with previous reports of a lack of association between this polymorphism and major psychiatric disorders. [source]

Interferon-, +874A/T and interleukin-4 intron3 VNTR gene polymorphisms in Chinese patients with idiopathic thrombocytopenic purpura

EUROPEAN JOURNAL OF HAEMATOLOGY, Issue 3 2007
Xiaoli Chen
Abstract Objectives:, The polarization of Th1/Th2 towards Th1 contributes to the pathogenesis of idiopathic thrombocytopenic purpura (ITP). Cytokines may play crucial roles in the pathogenesis of ITP. The purpose of this study was to investigate whether the interferon (IFN)-, +874(A/T) and interleukin-4 (IL-4) variable number of tandem repeats (VNTR) in intron3 polymorphisms may be responsible in part for genetic susceptibility to ITP. Methods:, Genotyping of IFN-, +874A/T and IL-4 intron3 VNTR was performed in 196 patients with ITP and 128 healthy individuals by polymerase chain reaction sequence-specific primers and direct PCR respectively. Results:, There was no association between IFN-, +874A/T and IL-4 intron3 VNTR polymorphism and ITP risk when all patients, as a group, were analyzed. When the patients were subdivided into two groups: childhood ITP and adult ITP, no statistical differences were found in the genotype and allele frequencies of IFN-, +874A/T and IL-4 intron3 VNTR between the two groups and the controls. Similar results were observed between acute childhood ITP, chronic childhood ITP, acute adult ITP or chronic adult ITP and the controls. Conclusion:, These polymorphisms were distributed similarly between the patients with ITP and the controls, demonstrating that these two candidate gene polymorphisms are not attributed to ITP susceptibility. [source]

GENETIC STUDY: Association between dopamine transporter genotypes and smoking cessation: a meta-analysis

ADDICTION BIOLOGY, Issue 2 2007
John A. Stapleton
ABSTRACT This review assessed the evidence of an association between genotypes of the dopamine transporter (DAT1, SLC6A3) 3, untranslated region (3,UTR) variable number of tandem repeats (VNTR) and smoking cessation. Five studies (seven cohorts) comprising 2155 subjects were included in the meta-analysis. All gave data on the number of smokers who had stopped smoking and the number still smoking for those with one or more variant 9-repeat alleles and other genotypes. Three studies (comprising five cohorts) were cross-sectional population surveys and two were smoking cessation treatment programs with follow-up. Four of the five studies (six of the seven cohorts) showed a trend in favor of cessation when the variant 9-repeat allele was present, although only one study showed a statistically significant effect. The pooled odds ratio in favor of a greater likelihood of cessation for the variant 9-repeat allele was 1.15 [95% confidence interval (CI) = 0.97,1.37]. In a more refined analysis where cohorts within studies were treated as separate samples and adjusted odds ratios were used, the overall pooled odds ratio in favor of cessation with the 9-repeat alleles was 1.20 (95% CI = 1.01,1.43). These results support the hypothesis that the DAT1 3,UTR VNTR polymorphism is associated with smoking cessation. One or more variant 9-repeat alleles relative to the more common 10-repeat allele confers a greater likelihood of cessation, indicative of lower dependence on tobacco. The effect was a 20% increase in the odds of cessation for those with a variant allele. [source]

An intron 4 VNTR polymorphism of the endothelial nitric oxide synthase gene is associated with early-onset colorectal cancer

INTERNATIONAL JOURNAL OF CANCER, Issue 7 2009
Chih-Ching Yeh
Abstract Endothelial-derived nitric oxide, which is produced by endothelial nitric oxide synthase (eNOS), may play an important role in colorectal carcinogenesis. However, the putative contribution of common eNOS genetic polymorphisms to colorectal cancer risk remains unknown. We genotyped 3 polymorphisms of eNOS (T-786C, G894T, and intron4b/a) in 727 colorectal adenocarcinoma cases and 736 age- and sex-matched healthy controls in Taiwan. Genotypes of the T-786C and G894T polymorphisms were determined by fluorescence polarization assays and the 27-bp variable number of tandem repeat (VNTR) polymorphism in intron 4 (intron4b/a) was analyzed by PCR. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Among younger participants (,60 yrs), the intron4a variant genotype was associated with a significantly increased risk of colorectal cancer, compared with the intron4bb genotype (OR = 1.60, 95% CI = 1.04,2.46). In addition, those young individuals bearing a greater number of high-risk genotypes (OR > 1, i.e., CT+TT for T-786C, ba+aa for intron4b/a, and GG for G894T) of eNOS had a higher colorectal cancer risk (ptrend = 0.039). Compared with younger individuals without any putative high-risk genotypes, those with 3 high-risk genotypes had a significantly greater cancer risk (OR = 1.89, 95% CI = 1.04,3.43). Our results suggest that the eNOS intron4b/a polymorphism may contribute to early-onset colorectal cancer risk in the Taiwanese population. © 2008 Wiley-Liss, Inc. [source]

Association of serotonin transporter gene-linked polymorphic region and variable number of tandem repeat polymorphism of the serotonin transporter gene in lichen simplex chronicus patients with psychiatric status

INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 10 2008
Necmettin Kirtak MD
Background, The serotonin (5-hydroxytryptamine; 5-HT) is a key neurotransmitter in the central nervous system and a responsible mediator for the itch. Dysregulation of serotonergic pathways has been implicated in the pathogenesis of many complex neuropsychiatric diseases. Objectives, The purpose of this study was to evaluate the relationship between lichen simplex chronicus and dysfunction and serotonin transporter (5-HTT) gene polymorphism. Methods, Thirty-nine patients with lichen simplex chronicus and 61 healthy control subjects were examined. Results, The results for the patients and control subjects were not significantly different (P > 0.05) in long/long (L/L) and long/short (L/S) genotypes of 5-HTT gene-linked polymorphic region (HTTLPR) polymorphism, but short/short S/S genotype was lower in lichen simplex chronicus patients (17.9%) than in controls (42.6%). This difference was statistically significant (P = 0.028). The results for the patients and control subjects were not significantly different in 12/12, 10/12 and 10/10 genotypes of variable number of tandem repeat (VNTR) polymorphism (P > 0.05). Beck depression inventory (BDI) scores and symptom checklist-90-revised (SCL-90) psychotic subscale were overrepresented significantly in the 12/12 genotypes than 10/12 genotypes. State and Trait Anxiety Inventory tests (STAI-I and -II) point averages were not statistically significant (P > 0.05) Conclusion, S/S genotypes of HTTLPR polymorphism in the 5-HTT gene may be related to lichen simplex chronicus and that patients who have 12/12 genotypes of VNTR polymorphism may be affected psychiatrically. [source]

A DRD4/BDNF gene,gene interaction associated with maximum BMI in women with bulimia nervosa

INTERNATIONAL JOURNAL OF EATING DISORDERS, Issue 1 2008
Allan S. Kaplan MD, FRCP(C)
Abstract Objective: The goals of the current study were threefold: 1) to examine whether the hypofunctional 7R allele of the DRD4 gene contributes to maximal lifetime body mass in women with BN; 2) to determine whether the BDNF gene contributes to maximal BMI on its own, and 3) to explore possible BDNF/DRD4 gene-gene interactions in mediating maximum lifetime BMIs in BN. Method: We tested two General Linear Models predicting maximum lifetime BMI with the exon 3 VNTR polymorphism of the dopamine-4 receptor gene (DRD4) and either the Val66Met or the -270C/T polymorphism of BDNF respectively in 163 female probands with BN, purging subtype. Results: In these bulimic subjects, the hypofunctional 7R allele of DRD4 predicted maximal BMI (p < .01). There was also a significant interaction between the DRD4 gene and the BDNF gene in predicting maximal BMI. The Val66Met rather than the 270C/T polymorphism of BDNF interacting with DRD4 predicted maximum BMI in this BN sample (p < .01). Probands carrying both the hypofunctional 7R allele of DRD4 and the Met66 allele of BDNF had significantly higher maximal BMI than did probands in the other gene-gene interaction groups. Conclusion: These results provide further evidence that the hypofunctional 7R allele of DRD4 contributes to weight gain in women with BN and that the BDNF gene interacts with DRD4 to influence weight regulation in these subjects. © 2007 by Wiley Periodicals, Inc. Int J Eat Disord 2008 [source]

Study on VNTR polymorphism of gene IL-1RA in 19 Chinese populations

INTERNATIONAL JOURNAL OF IMMUNOGENETICS, Issue 2 2010
J. Jiang
Summary Earlier studies suggested that a variable number tandem repeat (VNTR) polymorphism in intron 2 of the interleukin-1 receptor antagonist (IL-1RA) gene might be associated with some chronic inflammatory diseases, autoimmune diseases and solid tumours. To study the distribution of this polymorphism in China, 1352 samples were collected from 19 widely distributed Chinese populations. PCR was used to genotype the VNTR. The overall frequencies of allele 1 and allele 2 were 0.913 and 0.064 respectively. The frequency of the allele 2 was significantly different between the northeastern and the northwestern populations. Moreover, the allele frequencies at this locus in three Chinese Han populations were different from that in minority populations. When compared with other populations worldwide, the frequencies of the two alleles in China were not significantly different from those in the Asian and Pacific Islands. However, the prevalence of allele 1 in China was significantly higher, and the prevalence of allele 2 was significantly lower, than those in American and European Caucasians, and the pairwise Fst values reinforced this observation. The differences of the allele frequencies between different regions and within the same region showed that geography and race have important roles in the population differentiation for the IL-1RA gene. In summary, our results provide a valuable reference for population genetic information and future disease association studies in Chinese populations. [source]

Molecular analysis of HumDN1 VNTR polymorphism of the human deoxyribonuclease I in systemic lupus erythematosus

INTERNATIONAL JOURNAL OF IMMUNOGENETICS, Issue 1 2010
Suad AlFadhli
Summary Deoxyribonuclease I (DNASE1) may be responsible for the removal of DNA from nuclear antigens at sites of high cell turnover, thus preventing the onset of systemic lupus erythematosus (SLE). The purpose of this study was to screen DNASE1 gene for mutations that may have an effect on susceptibility to develop SLE. DNA was extracted from 76 Kuwaiti SLE patients and 92 race-matched controls. PCR-direct sequencing was used to screen DNASE1 promoter, coding sequence and exon,intron boundaries for mutation. Association of genomic variations was assessed using a Chi-square test. Molecular analysis of the DNASE1 gene did not reveal any mutation. However, a 56-bp repeat was detected in intron4 which was previously reported and named HumDN1. The allelic and genotypic distributions of the HumDN1 VNTR were compared between SLE patients and healthy subjects. Alleles were denoted as 2, 3, 4, 5 and 6 corresponding to the number of repeats of the 56 bp unit. Alleles 4, 5, and 6 showed significant association with SLE. Allele 5 showed the highest association [,2 = 32.57; P , 0.001; OR = 4.16; 95% CI: (2.55,6.79)]. Association of allele 5 was also found at the genotypic level, where genotype 5/5 is more prevalent in SLE subjects as compared with controls (17% versus 9%). We report a significant association of HumDN1 VNTR polymorphism in DNASE1 gene with SLE. Further functional assays needed to assess the effect of this VNTR on DNASE1 activity and its association with SLE. [source]

The 3, Part of the Dopamine Transporter Gene DAT1/SLC6A3 Is Associated With Withdrawal Seizures in Patients With Alcohol Dependence

ALCOHOLISM, Issue 1 2008
Yann Le Strat
Background: Some studies have reported that the A9 allele of the variable nucleotide tandem repeat (VNTR) of the gene which encodes the dopamine transporter (DAT1/SLC6A3) is associated with alcoholism withdrawal symptoms such as alcohol withdrawal seizures (WSs), whereas others did not. We investigated whether polymorphisms within the DAT1 gene are associated with WS taking into account some of the confounding factors such as the severity of alcohol dependence. Methods: To further assess the role of this gene in WS, we genotyped the VNTR and 7 single nucleotide polymorphisms (SNPs) encompassing the DAT1 gene in a sample of 250 alcohol-dependent subjects (175 men and 75 women), of whom 24% exhibited WSs, taking into account the severity of alcohol dependence. Results: The VNTR is associated with an increased risk of WSs (odd ratio = 3.5; p = 0.019), even when controlling for confounding factors (p = 0.031). As 2 SNPs, in roughly the same location of the gene (namely rs27072 and rs27048), are also associated with WSs, it is possible that the initial association of the VNTR polymorphism was tagging a specific haplotype of this gene. Indeed, in our sample of alcohol-dependent patients, 2 haplotypes were associated with a significantly different risk of WSs. Conclusions: The present study adds evidence for a significant role of the 3, part of the DAT1 gene in WS of alcohol-dependent patients, not only because it is in accordance with previous work, but also because of larger statistical power (as relying on a sample over sampled with the studied phenotype), as it gives a more precise analysis of different SNPs within the DAT1 gene, and as it confirms the association when major potentially confounding factors are taken into account in a logistical regression analysis. [source]

DRD4 and novelty seeking: Results of meta-analyses

AMERICAN JOURNAL OF MEDICAL GENETICS, Issue 6 2002
J.A. Schinka
Abstract Studies of the association between polymorphisms within and near the dopamine D4 receptor (DRD4) gene and novelty seeking (NS) have produced inconsistent results, raising questions about the strength of the relationship and the methodological conditions under which the relationship holds. We conducted three meta-analyses of existing studies to provide formal statistical measures of the strength of the DRD4-NS relationship. Results provided no support for a relationship between NS and the presence of the 7-repeat allele of the VNTR polymorphism. A small positive effect, however, was found for long repeats of the same polymorphism. The most promising findings were obtained for the relationship with the ,521 C/T promoter polymorphism, for which the analysis showed an effect size of 0.32. The positive findings are consistent with a polygenic model of influence on fundamental personality dimensions. © 2002 Wiley-Liss, Inc. [source]

Polymorphism of the promoter region of prostacyclin synthase gene in chronic thromboembolic pulmonary hypertension

RESPIROLOGY, Issue 2 2004
Shinya AMANO
Objective: Decreased expression of prostacyclin synthase (PGIS) is observed in the lung vasculature of patients with pulmonary arterial hypertension and the biosynthesis of prostacyclin (PGI2) may be impaired in chronic thromboembolic pulmonary hypertension (CTEPH). Whether it is genetically determined or develops as the disease progresses is unclear. A variable-number tandem repeat (VNTR) polymorphism has been detected in the 5,-upstream promoter region of the PGIS gene. It has been demonstrated that the alleles vary in size from three to seven repeats of nine base pairs, and transcriptional activity increased with the number of repeats. The purpose of the present study was to elucidate the association between the VNTR polymorphisms of the PGIS gene and CTEPH in Japanese subjects. Methodology: Ninety patients with CTEPH and 144 control subjects were investigated for the presence of VNTR polymorphisms. Sixty-two blood samples were obtained from CTEPH patients and the plasma concentrations of prostacyclin and thromboxane A2 metabolites were measured. Results: VNTR polymorphisms in the prostacyclin synthase gene were grouped into L alleles (five, six and seven repeats) and S alleles (three and four repeats). The overall distribution of the alleles and genotypes were not significantly different between CTEPH patients and the control subjects. The patients with the LL genotype had higher plasma concentrations of 6-keto-prostaglandin F1, than patients with the LS and SS genotypes. Conclusions: Our results suggested that the specific VNTR polymorphism in the 5,-upstream promoter region of the PGIS gene regulated prostacyclin production, but did not seem to be associated with the development of CTEPH in this patient population. [source]

NOD2/CARD15 and TNFA, but not IL1B and IL1RN, are associated with Crohn's disease

INFLAMMATORY BOWEL DISEASES, Issue 4 2005
António Carlos Ferreira BSc
Abstract Background:NOD2/CARD15 was described as the first susceptibility gene to Crohn's disease (CD). Polymorphisms in the TNFA gene and in the IL1 gene cluster, which are associated with an enhanced chronic inflammatory response, may also play a role in the development of CD. The aim of this study was to determine the association of polymorphisms in the CARD15, TNFA, IL1B, and IL1RN genes with risk of development of CD and with the clinicopathological profile of CD patients. Methods: In a case-control study including 235 CD patients and 312 controls (929 controls for TNFA genotyping), the CARD15 (R702W, G908R, and1007fs), TNFA (,308G/A and ,857C/T), IL1B (,511C/T), and IL1RN (intron 2 variable number of tandem repeats) polymorphisms were genotyped. Results: We observed a significant association between CD and the CARD15 polymorphisms, with an odds ratio (OR) of 2.9 [95% confidence interval (CI), 1.9 to 4.6] for carriers of 1 variant allele and an OR of 11.8 (95% CI, 3.5 to 40.4) for carriers of 2 variant alleles. Patients with CARD15 polymorphisms had more frequently ileal or ileocolonic disease location, stricturing phenotype, abdominal surgery, and no extraintestinal manifestations. The TNFA -308A/A genotype was associated with susceptibility to CD with an OR of 3.0 (95% CI, 1.2 to 7.2). TNFA -308A/A homozygotes showed a higher frequency of erythema nodosum and arthritis, colonic disease location, and absence of abdominal surgery. No associations were found with the TNFA -857, IL1B -511, and the IL1RN VNTR polymorphisms. Conclusions: These findings suggest that CARD15 and TNFA -308 genetic polymorphisms are associated with increased risk of CD displaying distinct clinicopathological profiles. [source]

Variable number of tandem repeats polymorphism of platelet glycoprotein Ib , in Chinese people and CC genotype with aspirin sensitivity in patients with cerebral infarction

JOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 2 2009
Y.-Y. Jin MM
Summary Background and objective:, To study the prevalence of variable number of tandem repeats (VNTR) polymorphism in platelet membrane glycoprotein (GP) Ib , in a Chinese Han population and to determine the relationship between VNTR polymorphisms and aspirin resistance. Methods:, Three hundred healthy individuals and 110 patients with cerebral infarction volunteered to participate in this study. The genotype status of all participants was determined by polymerase chain reaction-restriction fragment length polymorphism analysis. Platelet aggregation in patients with cerebral infarction receiving aspirin (100 mg/day) for at least 7 days, was measured by optical transmission aggregometry. Results and discussion:, Only three alleles of GP Ib ,, namely, B, C and D, were found. Type A was not found in the Chinese Han participants. Aspirin-sensitive patients were significantly more often of CC genotype than aspirin-semi-responders. Conclusions:, Only three types of alleles B, C and D were detected in the north-eastern region of China. The CC genotype of the VTNR polymorphism in GPIb appears to be more sensitive to the inhibitory action of low-dose aspirin. [source]