Studied Polymorphisms (studied + polymorphism)

Distribution by Scientific Domains


Selected Abstracts


Catechol-O-methyltransferase val108/158met genotype and response to antipsychotic medication in schizophrenia

HUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 4 2007
Ari Illi
Abstract Catechol-O-methyltransferase (COMT) gene has been investigated as a possible candidate gene in schizophrenia. The most studied polymorphism has been the functional val108/158met polymorphism of this COMT gene. There is also some evidence that this polymorphism could be related to drug response to antipsychotics in schizophrenia. COMT enzyme inactivates dopamine and noradrenaline. Based mainly on the original dopamine theory of schizophrenia, our primary hypothesis was that the maintenance dose of antipsychotics would be higher in patients with the low activity COMT genotype. In this study we evaluated the current daily dosage of antipsychotics in 180 patients with schizophrenia in connection with the COMT genotype. We could not demonstrate any clearly significant effect of this particular COMT genotype in relation to the daily maintenance dosages of antipsychotics in patients with schizophrenia. Copyright © 2007 John Wiley & Sons, Ltd. [source]


TNF-, and intPLA2 genes' polymorphism in anorexia nervosa

ACTA NEUROPSYCHIATRICA, Issue 6 2004
Agnieszka Slopien
Objective:, The aim of this study was the assessment of ,308G/A tumor necrosis factor (TNF)- , gene polymorphism and intPLA2 gene polymorphism in patients with anorexia nervosa (AN) and healthy controls. Subjects:, We studied 91 non-related patients with AN and 144 healthy women (blood donors and students). The mean age of women from study group was 18.22 years (SD ± 3.13 years) and from control group was 31.71 years (SD ± 8.22). Methods:, ,Gene polymorphisms were studied with the use of polymerase chain reaction-restriction fragment length polymorphism method. TNF-, gene polymorphism consists of G/A substitution in ,308 promoter region. IntPLA2 gene polymorphism is related to intron 1, in which restrictive region is found and recognized by BanI enzyme. Results:, We did not obtain statistically significant differences in the frequency of genotypes and alleles of ,308G/A TNF-, polymorphism between the study and control groups (genotypes: P = 0.106, alleles: P = 0.076). We did analogous analysis in the restrictive and bulimic subgroups. We did not observe statistically relevant differences in the frequency of genotypes (P = 0.700) and alleles (P = 0.305). We did not obtain statistically relevant difference in the frequency of genotypes and alleles of intPLA2 gene between the study group and controls (genotypes: P = 0.300, alleles: P = 0.331). We did analogous analysis in both subgroups of AN. We did not observe statistically relevant differences in the frequency of genotypes (P = 0.344) and alleles (P = 0.230). Conclusions:, There was no statistically relevant trend for the association between TNF-, polymorphism and AN. We did not find association between studied polymorphism of intPLA2 gene and risk of AN. [source]


H intragenic polymorphisms and haplotype analysis in the ornithine transcarbamylase (OTC) gene and their relevance for tracking the inheritance of OTC deficiency,,

HUMAN MUTATION, Issue 5 2002
Consuelo Climent
Abstract The "private" nature of most mutations causing ornithine transcarbamylase (OTC) deficiency makes mutation identification in the patients difficult. Further, the PCR-amplification technology generally used for the genetic diagnosis of the deficiency misses large deletions in carrier females. Intragenic OTC polymorphisms may allow detection of these deletions and may represent an alternative to mutation detection for prenatal diagnosis and carrier identification in families with a history of inherited OTC deficiency. A new highly informative polymorphism (allele frequencies, 0.66/0.34) in intron 3 of the OTC gene (IVS3-39_40insT) is reported here, and allelic frequencies of 16 additional intragenic OTC polymorphisms are determined in 133-35 (average per polymorphism, 72) unrelated chromosomes. In addition to the novel polymorphism, only three of the studied polymorphisms (Lys46Arg, allelic frequency 0.68/0.32; IVS3-8A>T, 0.34/0.66; Gln270Arg, 0.97/0.03) are confirmed to be informative. These provide, together with another reported polymorphism (IVS4-7A>G; reported allelic frequency 0.71/0.29; Plante and Tuchman, 1998), a set of highly valuable markers of the OTC gene. Nevertheless, the combined informativity of the studied polymorphisms is limited by their distribution in only four haplotypes with one of them predominating (65% of the sampled chromosomes). Although this haplotype composition may be restricted to the Iberian peninsula (the origin of the samples), more informative polymorphisms are required to increase the diagnostic potential and, particularly, to identify large deletions affecting OTC gene exons 5-10, where only one polymorphism of weak diagnostic value is known. © 2002 Wiley-Liss, Inc. [source]


The influence of polymorphisms of VKORC1 and CYP2C9 on major gastrointestinal bleeding risk in anticoagulated patients

BRITISH JOURNAL OF HAEMATOLOGY, Issue 5 2008
Ramón Montes
Summary The VKORC1 c.,1639G>A and CYP2C9 c.430C>T and c.1075A>C polymorphisms have been associated with increased sensitivity to oral anticoagulants. However, their role in gastrointestinal bleeding is unknown. We studied the risk of gastrointestinal bleeding associated with these polymorphisms, and how this risk was influenced by the anticoagulant dose and the use of common drugs. Eighty-nine patients with gastrointestinal bleeding during acenocoumarol therapy and 177 patients free of bleeding during acenocoumarol therapy were studied. None of the three polymorphisms constituted a serious gastrointestinal bleeding risk factor. However, patients bearing at least one of these polymorphisms were at high risk, when they simultaneously met one of the following conditions: a weekly dose of acenocoumarol higher than 15 mg [adjusted Odds Ratio (OR) (95% confidence interval (CI) = 4·19 (1·59,11·04)]; amiodarone use [adjusted OR (95% CI) = 9·97 (1·75,56·89)]; or aspirin use [adjusted OR (95% CI) = 8·97 (1·66,48·34)]. The consumption of statins was associated with a lower risk of gastrointestinal bleeding [adjusted OR = 0·50 (0·26,0·99)]. The risk of gastrointestinal bleeding during acenocoumarol therapy in carriers of any of the studied polymorphisms is severely increased with exposure to weekly doses of acenocoumarol higher than 15 mg or the use of amiodarone or aspirin. [source]


Polymorphisms in ERCC2, MSH2, and OGG1 DNA repair genes and gallbladder cancer risk in a population of Northern India

CANCER, Issue 13 2010
Kshitij Srivastava MSc
Abstract BACKGROUND: Genetic variants of DNA repair enzymes may lead to genetic instability and contribute to gallbladder (GB) carcinogenesis. METHODS: A case-control study (230 GB carcinogenesis patients and 230 controls) was undertaken to evaluate whether genetic variations in 3 DNA repair genes ERCC2 (Asp312Asn [rs1799793] and Lys751Gln [rs13181]), MSH2 (,118T>C [rs2303425] and IVS1 + 9G>C [rs2303426]), and OGG1 (Ser326Cys [rs1052133] and 748-15C>G [rs2072668]) are associated with GB carcinogenesis risk in a North Indian population. RESULTS: The authors found that the ERCC2 Asp312Asn AA, MSH2 IVS1 + 9G>C CC, OGG1 Ser326Cys GG and CG + GG, and OGG1 748-15C>G GG and CG + GG genotypes were significantly associated with an increased risk of GB carcinogenesis (odds ratio [OR], 2.1, 1.8, 2.5, 1.8, 2.0, and 1.6, respectively). In contrast, ERCC2 Lys751Gln, and MSH2 ,118T>C markers showed no significant associations with GB carcinogenesis risk, although because of the small sample size their effects cannot be ruled out. Female GB carcinogenesis patients with the OGG1 748-15C>G GG, OGG1 Ser326Cys GG, and ERCC2 Asp312Asn genotypes had a greater risk for developing the disease (OR, 3.6, 7.7, and 2.7, respectively). There was a significant interaction between MSH2 IVS1 + 9G>C and OGG1 748-15C>G polymorphisms (P = .001). Furthermore, individuals with >6 variant alleles of the studied polymorphisms were at 4-fold increased risk for developing GB carcinogenesis. Classification and Regression Tree analysis revealed potential higher-order gene-gene interactions and categorized a few higher-risk subgroups for GB carcinogenesis. CONCLUSIONS: These results suggest that genetic variants in the DNA repair pathways may be involved in GB carcinogenesis etiology. Cancer 2010. © 2010 American Cancer Society. [source]