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Results for “Genetic polymorphisms”

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PubMed1988

Evidence of loss of a suggested genetic polymorphism in the blood potassium contents of zoo-living Barbary sheep Ammotragus lervia (Pallas 1777).

1. Concentrations of potassium and iron were measured in blood samples of 15 zoo-living Barbary sheep by atomic absorption spectrophotometry. 2. In analogy with the situation in Ovis it is suggested that a blood potassium polymorphism is also found in Ammotragus. 3. However, in the Frankfurt line at least, one of the presumed alleles is likely to be lost due to inbreeding.

Animals↗
PubMed1992

Presence and genetic polymorphism of an epithelial mucin in milk of the goat (Capra hircus).

1. Analysis of individual samples of goat's milk by SDS-PAGE confirmed that they contain a polymorphic, high molecular weight (M(r) greater than 205 kDa) glycoprotein. 2. On SDS-gels, the polymorphism takes the form of two bands of variable mobility which usually stain with equal intensity. This polymorphism resembles that detected in milk mucins of other species and is best explained by an expression of codominant genes containing variable numbers of a tandemly repeated 60-base segment. 3. Analysis of milk fractions provided evidence that the goat mucin is exclusively a membrane protein, and that it can be purified from other fat globule proteins by gel filtration and peanut lectin affinity chromatography. 4. Among proteins in the goat milk fat globule, the mucin appears to be a strong immunogen but the resulting antibodies applied to Western blots only stained the cow's milk mucin mildly and the guinea pig and human milk mucins not at all.

Animals↗
PubMedDate not supplied

Ethanol-inducible cytochrome P4502E1: genetic polymorphism, regulation, and possible role in the etiology of alcohol-induced liver disease.

In the Tsukamoto-French model, ethanol causes an important 10-20-fold induction of ethanol-inducible cytochrome P4502E1 (CYP2E1), mediated through enzyme stabilization and increased rate of gene transcription. The CYP2E1 induction results in a pronounced increase in the rate of NADPH-dependent microsomal lipid peroxidation, an elevation which is not seen after simultaneous administration of the CYP2E1 inhibitor diallylsulfide. Increased amounts of lipid peroxides are seen in plasma and red blood cells of both rats and humans during high ethanol intake. A mechanism for ethanol-dependent liver damage is proposed which involves the CYP2E1-dependent lipid peroxide formation, either directly by its capability to induce NADPH-dependent peroxidation in the microsomal membranes or indirectly by a hypoxia-mediated transformation of xanthine dehydrogenase to xanthine oxidase, in activation of Ito cells and Kupffer cells to yield cytokine and collagen production. The CYP2E1 gene is polymorphic among Caucasians. Four different unrelated or partially linked polymorphisms have been observed. One polymorphism in the 5'-flanking region has been described to be associated with altered enzyme expression in vitro, and the rare allele was found to be less frequent among Swedish patients having lung cancer when compared to two different control groups. Another polymorphism, detectable with Dra I restriction endonuclease fragment length polymorphism (RFLP), was localized to intron 6, and the rare allele was less common among Italian alcoholics with clinical signs of liver cirrhosis, as compared to controls. Several other mutations in the CYP2E1 gene were found to be associated with this allele. However, further research is needed to relate the CYP2E1 gene polymorphism with incidence of liver cirrhosis.

Animals↗
PubMedDate not supplied

Genetic polymorphism of rabbit VHa region: a new allotype, a108.

We report a new rabbit IgVH allotype, designated a108, which was detected following studies of the progeny of a wild rabbit (Oryctolagus cuniculus) from Zembra Island (Tunisia). This allotype seems to be specific of this island, since it has not been detected in other wild rabbit populations (in Spain, Portugal or France). Its determinants are located on the Fd fragment of the immunoglobulin (Ig) heavy chain and it behaves like the product of an allele at the alpha locus. Allotype a108 was strongly related serologically to a1 and a107, and to a lesser extent to a101, a109 and a3 allotypes. We also detected determinants shared among the a1, a107, a108, a101 and a109 allotypes. These determinants were expressed by a large fraction of Ig molecules from rabbits of allotype a1, a107 and a108 and by a very small fraction of Ig from rabbits of allotype a101 and a109.

Animals↗
PubMed2005

Methylenetetrahydrofolate reductase genetic polymorphisms in patients with cataract.

PURPOSE: Hyperhomocysteinemia is commonly associated with polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene. The level of homocysteine can be lowered by dietary intake of folate. A protective effect of folate supplementation has been reported against cataract. Here we investigate MTHFR polymorphisms in human cataract. DESIGN: Retrospective case-control association study. METHODS: Patients with nuclear (n = 77), cortical (n = 155), posterior subcapsular (n = 119), and mixed (n = 151) cataract, and 187 controls were analyzed for the MTHFR 677C-->T and 1298A-->C polymorphisms using minisequencing technique. RESULTS: The wild-type MTHFR 677CC/1298AA genotype was strongly overrepresented among cataract cases (P = .003). This effect was most pronounced in the mixed cataract group (P < .001). Hyperhomocysteinemia-associated genotypes had similar frequencies in cataract and control groups. CONCLUSIONS: The previously reported protective effect of folate against cataract is not due to overrepresentation of hyperhomocysteinemia-associated MTHFR genotypes. Instead, the strong predominance of wild-type MTHFR in cataract may suggest impaired DNA synthesis as a cataractogenic factor.

Adult↗
PubMed2004

Interactions between common genetic polymorphisms in ABCG5/G8 and CYP7A1 on LDL cholesterol-lowering response to atorvastatin.

Cholesterol excretion by ATP binding cassette transporters G5 and G8 (ABCG5/G8) and bile acid biosynthesis by cholesterol 7alpha-hydroxylase (CYP7A1) are major pathways for the removal of cholesterol into bile. To investigate the interactions between common polymorphisms in ABCG5/G8 and CYP7A1 and statin response, we examined the relationships between five non-synonymous polymorphisms in ABCG5/G8 (Q604E, D19H, Y54C, T400K, and A632V) and a promoter variant in CYP7A1 (A-204C) in 337 hypercholesterolemic patients treated with atorvastatin 10mg. The ABCG8 H19 allele was significantly associated with a greater LDL cholesterol reduction relative to the wild type D19 allele (39.6% versus 36.6%, P = 0.043). This difference was enhanced in non-carriers of the CYP7A1 promoter polymorphism (42.7% versus 38.2%, P = 0.048), and was diminished in accordance with the number of CYP7A1 variant alleles (1.8% in heterozygotes and 0.2% in homozygotes). Combination analysis of these polymorphisms explained a greater percentage of LDL cholesterol response variation (8.5% difference across subgroups) than did single polymorphism analysis (4.2% in CYP7A1 and 3.0% in ABCG8 D19H). The other ABCG5/G8 polymorphisms did not show any significant interactions with the CYP7A1 polymorphism. We conclude that the ABCG8 H19 and CYP7A1 C-204 alleles appear to interact in a dose-dependent manner on atorvastatin response.

ATP Binding Cassette Transporter, Subfamily G, Mem↗
PubMed2004

The finding of new genetic polymorphism of UCP-1 A-1766G and its effects on body fat accumulation.

A-1766G polymorphism, for the first time, has been found in the sequencing of pooled and individual genomic DNA of Korean subjects at the 5' flanking region of the UCP-1 gene. The effects of new polymorphism on body fat were elucidated among 387 Korean female subjects. It was shown that the genotypes AA, AG, and GG were consisted of 57.4%, 37.7%, and 4.9%, respectively, which was in agreement with Hardy-Weinberg equilibrium (P=0.327). The frequency of major A allele was 0.762 and that of minor G allele was 0.238. It is found that the waist-hip ratio (WHR) (P=0.008), body fat mass (P=0.023), and percent body fat (P=0.014) are significantly higher in the AG/GG type compared to the AA type. When the subjects were analyzed using computerized tomography, there were significant increases in the AG/GG type compared to the AA type in the abdominal subcutaneous fat (P=0.015) and the abdominal visceral fat (P=0.013), respectively. A-1766G is approximately 2 kb downstream from the well-known A-3826G polymorphism, and no linkage between them was found (D'=0.929, R(2)=0.283). Three haplotypes (frequency >0.05) were examined from two polymorphisms and studied for their physiological effects. It was found that haplotype [GG] was significantly associated with increased body fat, while haplotype [GA] was associated with decreased body fat.

Adipose Tissue↗
PubMed2004

Functional characterization of genetic polymorphisms identified in the human cytochrome P450 4F12 (CYP4F12) promoter region.

The human cytochrome CYP4F12 has been shown to be active toward inflammatory mediators and exogenous compounds such as antihistaminic drugs. In the present study, we report the first investigation of polymorphisms in the human CYP4F12 gene. A screening for sequence variations in the 5'-flanking region was performed by a Polymerase Chain Reaction-Single Strand Conformational Polymorphism (PCR-SSCP) strategy, using DNA samples from 53 unrelated French individuals of Caucasian origin. Several polymorphisms were identified, comprising a large deletion located in intron 1 (CYP4F12*v1), two isolated substitutions -402G>A (CYP4F12*v3) and -188 T>C (CYP4F12*v4) and nine combined mutations, -474T>C, -279A>C, -224A>G, -173G>A, -145C>G, -140T>C, -126T>C, -56T>C, and -21T>G (CYP4F12*v2). Considering the nature and location of the polymorphisms characterizing the CYP4F12*v1 and *v2, the functional relevance of those two allelic variants was further examined by transfecting different cell lines with constructs of the related region of the CYP4F12/luciferase reporter gene. Both alleles lead to a significant decrease of CYP4F12 gene expression in HepG2 cell line and, therefore, are likely to determine interindividual differences in CYP4F12 gene expression.

Alleles↗
PubMed2005

Genetic polymorphism in the sulfotransferase SULT1A1 gene in cancer.

Cytosolic sulfotransferases are enzymes that catalyze the conjugation of sulfate groups to a variety of xenobiotic and endogenous substrates. A mutation in the SULT1A1 gene has been associated with decreased sulfotransferase activity. We studied 125 cancer patients and 100 healthy controls from Brazil matched by age and gender. The objective of this study was to assess the impact of the SULT1A1 polymorphism on sulfotransferase activity in a population of cancer patients. Both heterozygous and homozygous individuals for the mutant allele had significantly decreased sulfotransferase enzymatic activity. This decrease was more significant in cancer patients. The frequency of the SULT1A1( *)2 allele was increased in the myeloma group (odds ratio=0.53). These data suggest a functional role for the SULT1A1 gene polymorphism in cancer.

Adult↗
PubMed2004

Investigation of genetic polymorphisms and smoking in a bladder cancer case-control study in Argentina.

We investigated the role of glutathione S-transferase (GST) enzymes (M1, T1), methylenetetrahydrofolate (MTHFR) 677 and 1298, and the NAD(P)H:quinone oxidoreductase (NQO1) polymorphisms in a population-based bladder cancer case-control study in Argentina. Buccal cell DNA was obtained from 106 cases and 109 controls. The strongest evidence was for an interaction between NQO1 genotype and smoking. For ever smoking vs. never smoking the odds ratio was 8.6 (95% confidence interval (CI) 2.7-27), in the CC genotype, and 1.3 (95% CI 0.5-3.5) in the CT and TT genotypes combined. Also, elevated bladder cancer risks associated with GSTM1 and GSTT1 null genotypes were found in smokers. Having both null polymorphisms conferred the highest risks. The MTHFR 677 CT and TT polymorphisms appeared protective against bladder cancer.

Adult↗
PubMed2005

Genetic polymorphisms in CYP1B1, GSTA1, NQO1 and NAT2 and the risk of lung cancer.

In a population-based case-cohort study, we have investigated the occurrence of lung cancer in relation to polymorphisms in the phase I gene cytochrome P450 1B1 and in the phase II genes glutathione S-transferase A1, NAD(P)H quinone oxidoreductase and N-acetyltransferase 2 (NAT2). Among 54,220 cohort members, 265 lung cancer cases were identified and a sub-cohort comprising 272 individuals was used for comparison. No overall associations were found between the polymorphisms and risk of lung cancer. The NAT2 fast acetylator genotype seemed to be protective against lung cancer in light smokers (< or =20 cigarettes/day) and not among heavy smokers (>20 cigarettes/day).

Aged↗
PubMed2006

Does occupational exposure to PAHs, diesel and aromatic amines interact with smoking and metabolic genetic polymorphisms to increase the risk on bladder cancer?; The Belgian case control study on bladder cancer risk.

To investigate the association between occupational exposure to polycyclic aromatic hydrocarbons, aromatic amines and diesel and bladder cancer risk and the modification by smoking and metabolic polymorphisms, have we recruited 200 cases and 385 population controls. The adjusted OR of bladder cancer was 5.75 (95%CI 2.09-15.83) comparing the highest tertile of the cumulative probability of occupational exposure to aromatic amines with no occupational exposure. A possible interaction between occupational exposures to aromatic amines and smoking was found. The increased ORs of GSTM1, GSTT1, NAT2 and SULT1A1 among those ever occupational exposed was explored by estimating the false-positive report probability. We confirm that occupational exposure to aromatic amines is associated with an increase in bladder cancer risk.

Aged↗
PubMed2005

Genetic polymorphism of matrix metalloproteinase (MMP)-9 does not affect plasma MMP-9 activity in healthy subjects.

BACKGROUND: Plasma MMP-9 levels have been shown to predict cardiovascular risk, and a functional substitution C to T at position -1562 in the promoter region of the MMP-9 gene has been associated with the severity of cardiovascular diseases. We examined the association between the C(-1562)T polymorphism and MMP-9 activity in healthy subjects. METHODS: We studied 200 healthy male white volunteers (age range: 20-55 y) who were nonsmokers and were not taking medicines. Genomic DNA was extracted and genotypes for the C(-1562)T polymorphism were determined by PCR and restriction fragment length digestion. Plasma was assayed for pro-MMP-9 and MMP-9 activities by gelatin zymography. RESULTS: The frequency of the alleles "C" and "T" were 90% and 10%, respectively. Because of the relatively low frequency of the TT genotype, we combined both TT and CT genotypes together (CT+TT group) and compared with the CC genotype group. We found no differences in pro-MM9 and MMP-9 activity levels among the genotype groups (both P>0.05). CONCLUSIONS: While the present study indicates lack of effect for the C(-1562)T polymorphism on MMP-9 activity in plasma, it is possible that the C(-1562)T polymorphism contributes to an increased cardiovascular risk under conditions of induced MMP-9 expression.

Adult↗