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Lack of association between human longevity and genetic polymorphisms in drug-metabolizing enzymes at the NAT2, GSTM1 and CYP2D6 loci.

In the present study, the possible role of genetic polymorphism of three drug-metabolizing enzymes, debrisoquine/sparteine hydroxylase (CYP2D6), glutathione S-transferase mu (GSTM1), and N-acetyltransferase (NAT2), as a putative genetic component of human longevity, was explored. A total of 817 DNA samples from a centenarian and a control (20-70 years) population was subjected to PCR-coupled RFLP methods. Subjects were genotyped for the CYP2D6*3 (A2637 deletion) and CYP2D6*4 (G1934A transition) alleles, for four mutations of NAT2 [namely, NAT2*5A (C481T), NAT2*6A (G590A), NAT2*7A (G857A), and NAT2*14A (G191A)], and for the presence or absence of GSTM1 gene deletion. No significant difference was found at these three loci between centenarian and control subjects with respect to allelic variant frequencies, genotype distributions or predicted phenotypes deduced from genotype combinations. By comparing the distribution of combined genotypes for the polymorphisms tested at the CYP2D6, NAT2, and GSTM1 loci, none of the predicted phenotypes concerning debrisoquine hydroxylase extensive-metabolizer or poor-metabolizer phenotypes, slow or fast N-acetylation capacities, and active or defective glutathione S-transferase, could be correlated with human longevity, alone or in combination.

Adult↗

Distinctive effects of CCR5, CCR2, and SDF1 genetic polymorphisms in AIDS progression.

The Genetics of Resistance to Infection by HIV-1 (GRIV) cohort represents 200 nonprogressor/slow-progressor (Slowprog) and 90 fast-progressor (Fastprog) HIV-1-infected patients. Using this unique assembly, we performed genetic studies on three recently discovered polymorphisms of CCR5, CCR2, and SDF1, which have been shown to slow the rate of disease progression. The increased prevalence of mutant alleles among Slowprogs from the GRIV cohort was significant for CCR5 (p < .0001) but not for CCR2 (p = .09) or SDF1 (p = . 12), emphasizing the predominant role of CCR5 as the major HIV-1 coreceptor. However, the prevalence of the CCR2 mutant allele (64I) was significantly increased among Slowprogs homozygous for wild-type CCR5 compared with Fastprogs (p = .04). The prevalence of double mutants SDF1-3'A/3'A genotypes was also increased among Slowprogs homozygous for wild-type CCR5 compared with Fastprogs (p = .05). The effects of the CCR2 and SDF1 mutations are overshadowed by the protective effects of the CCR5 deletion. Predictive biologic markers such as CD4 cell counts or viral load in the Slowprog population did not show significant differences between Slowprog groups with wild-type or mutant alleles for the three genes. Thus, our data suggest that the effects of these genes are exerted earlier in infection and no longer evident in the Slowprog of the GRIV cohort whose average duration of HIV infection is 12 years. We conclude that these genes, whose products serve as viral coreceptors or their ligands, may play a role early in infection and delay the onset of disease. However, among Slowprogs, whose duration of infection is >8 years, they are no longer influential for maintenance of their longterm nonprogression status. Other genetic determinants may be responsible for late protective effects.

Acquired Immunodeficiency Syndrome↗

Genetic polymorphisms as biomarkers of sensitivity to inhaled sulfur dioxide in subjects with asthma.

BACKGROUND: Individuals with asthma are sensitive to inhaled sulfur dioxide (SO2); decrements in pulmonary function occur after exposure to low concentrations even for a short duration of time. There is a great amount of interindividual variation in response to SO2. OBJECTIVE: It was our objective to determine whether one of the following polymorphism locations linked with asthma is associated with the bronchial hyperresponsiveness to SO2 observed in some asthmatic patients: the beta2-adrenergic receptor, interleukin-4 (IL-4) receptor alpha subunit, Clara cell secretory protein (CC16), TNF-alpha gene promoter, and first intron of the lymphotoxin alpha (LT-alpha) gene. METHODS: Subjects were volunteers with physician-diagnosed asthma requiring regular asthma medication. Spirometry was performed before and after a 10-minute exposure to 0.5 ppm SO2. Subjects were classified as SO2 responders if forced expiratory volume in 1 second (FEV1) decreased > or = 12%. DNA obtained from buccal cell samples was analyzed for genetic polymorphisms. RESULTS: Of the 62 subjects (21 male and 41 female), 13 had a 12% or greater decrement in FEV1 after SO2 exposure (range + 19% to -49%). Response to SO2 was associated with the wild-type allele of the TNF-alpha promoter polymorphism (12 of 12 SO2 responders versus 28 of 46 nonresponders; P < .05) but with no other polymorphisms. Medication category and atopic status showed no association with SO2 sensitivity. CONCLUSIONS: The wild-type allele of the TNF-alpha promoter polymorphism may be associated with mechanisms of asthmatic sensitivity to inhaled SO2.

Administration, Inhalation↗

Biosynthesis of frog skin mucins: cysteine-rich shuffled modules, polydispersities and genetic polymorphism.

1. Frog integumentary mucins (FIM-A.1, FIM-B.1 and FIM-C.1) consist of typical threonine-rich highly O-glycosylated (semi)repetitive domains, and cysteine-rich modules, i.e. the P-domain, the short consensus repeat and a region with high similarity to the C-terminal end of von Willebrand factor (designated here CC29-motif). 2. These modules are thought to be involved in protein-protein interactions and they have been observed in a variety of extracellular proteins. In FIMs, these modules may be involved in oligomerization processes leading to an entangled mucin network. 3. Polydispersities have been detected in FIM-B.1 and FIM-C.1 within single individuals. Multiple transcripts are probably generated by alternative splicing of a huge array of different (semi)repetitive cassettes encoding the threonine-rich domains. 4. Furthermore, genetic polymorphism is observed between different individuals, probably due to allelic variations in the number of (semi)repetitive cassettes.

Alleles↗

Genetic polymorphism of human plasminogen in the Japanese population: new plasminogen variants and relationship between plasminogen phenotypes and their biological activities.

Genetic polymorphism of human plasminogen in the Japanese population has been described using polyacrylamide gel isoelectric focusing electrophoresis followed by immuno-fixation techniques. New variants PLG1'-1', PLG2'-1, and rare 1 were detected. Fibrinolytic activity per milligram plasminogen of each phenotype, except for PLG1'-1' and PLG1-1' was within the normal range. The PLG1' component was associated with no or less plasminogen activity, but possessed plasminogen antigen. Gene frequencies calculated from 750 individuals were PLG1;09560, PLG2; 0.0113, PLG1'; 0.0233, and PLG2',0.0094; respectively. The distribution of phenotypes fitted the Hardy-Weinberg equilibrium. In order to detect the plasminogen phenotypes the immunofixation technique was more suitable than the zymogram technique.

Genetic Variation↗

[Genetic polymorphisms and application of 9 STR loci of 5 ethnic groups in Gansu and Qinghai].

OBJECTIVE: To examine the genetic polymorphism of 9 STR loci in 5 ethnic groups (including Tu, Sala, Dongxiang, Baoan and Yugu) in Gansu and Qinghai, and to evaluate its application. METHODS: Nine STR loci (D3S1358, FGA, TH01, D7S820, VWA, CSF1PO, D5S818, D13S317 and TPOX) were selected as genetic markers. With STR compound amplification and genescan methods, in which STR loci were marked by fluorescence, the genotype of 5 ethnic groups were examined in 606 unrelated individuals by ABI 377 sequencer. These parameters, such as polymorphism information content (PIC), heterozygosity (H), discrimination power (DP) and probability of paternity exclusion (PPE) were calculated. RESULTS: The genotype frequencies of the 9 STR loci were in accordance with Hardy-Weinberg equilibrium. PIC was within 0.6054 - 0.8735, H was within 0.6158 - 0.8736, DP was within 0.7964 - 0.9691, and PPE was within 0.4610 - 0.8838. Cluster analysis based on allele frequencies in genesis showed Tu, Sala, Dongxiang and Baoan ethnic groups were very close, but Yugu was a little bit far. There were obvious gene exchanges among the populations in north and south of China. CONCLUSION: All the 9 STR loci are highly polymorphic in the 5 ethnic groups, which can be useful genetic markers in forensic medicine and population genetics.

China↗

Genetic polymorphism of xenobiotic metabolising enzymes in Slovenian lung cancer patients.

Most carcinogenic substances require metabolic activation in order to become ultimate carcinogens. Genetic polymorphism of xenobiotic metabolising enzymes cytochromes P450 may therefore influence human cancer susceptibility. The aim of our study was to investigate if CYP1A1 gene polymorphism contributes to lung cancer susceptibility in Slovenian patients. Two polymorphic sites in CYP1A1 gene were analysed in DNA samples from 100 healthy controls and 199 lung cancer patients using genotyping approach. Our results indicate that CYP1A1 may be one of the factors determining susceptibility to squamous cell carcinoma of lung in Slovenian population. However the frequency of CYP1A1 polymorphisms is too low to be a potentially useful marker of increased lung cancer risk.

Carcinoma, Squamous Cell↗

Can genetic polymorphism of alpha-2-macroglobulin be detected by immunoelectrophoresis? A study using sera, plasma and joint fluids from patients with rheumatoid arthritis and controls.

The technique of immunoelectrophoresis (IEP) was used to examine polymorphism of the endopeptidase inhibitor alpha-2-macroglobulin (alpha 2M) by measuring its electrophoretic mobility. Examination of the variability of the method showed that a large intra- and inter-plate variation occurred (3.3 and 11.6%, respectively). It was also shown that alpha 2M from plasma moves significantly slower than that from serum and that the mobility of alpha 2M from plasma can be increased to that of serum by treatment with trypsin. Upon comparing sera, plasma and synovial fluids from a control group (normal subjects and patients with osteoarthritis) with a group of patients with rheumatoid arthritis, no difference in alpha 2M mobility could be demonstrated. It is concluded that genetic polymorphism of alpha 2M cannot be detected by the technique of IEP.

Arthritis, Rheumatoid↗

Clinical correlation and genetic polymorphism of the human immunodeficiency virus proviral DNA obtained after polymerase chain reaction amplification.

Polymerase chain reaction (PCR) was used to amplify a long sequence of human immunodeficiency virus (HIV) DNA, to assess the correlation between PCR signal and clinical stage of disease, and to demonstrate the genotypic variability of different HIV isolates. Twenty-four (96%) of 25 anti-HIV-reactive patients and none of 12 controls were positive for HIV proviral DNA by PCR. After quantification of the PCR signal, a significant difference in the relative amount of HIV proviral DNA per 10(5) peripheral blood mononuclear cells between symptomatic patients (Centers for Disease Control [CDC] class IV) (32,284 +/- 5225 cpm [mean +/- SE], equivalent to 802 HIV plasmid DNA copies) and patients without symptoms (CDC class II/III) (5484 +/- 1469 cpm [mean +/- SE], equivalent to 67 HIV plasmid DNA copies) was observed (P less than .01). Restriction analysis of PCR products in selected samples showed extensive genetic polymorphism between different isolates and more than one viral genotype per isolate. There was a clear correlation between the appearance of clinical symptoms in HIV infection and high levels of viral replication.

Blotting, Southern↗

Bupropion and 4-OH-bupropion pharmacokinetics in relation to genetic polymorphisms in CYP2B6.

Bupropion is applied in depression and smoking cessation. Genetic polymorphisms in cytochrome P450 2B6 (CYP2B6) may cause variability in bupropion pharmacokinetics since hydroxylation is known to be mediated by CYP2B6. Bupropion may be a probe drug for CYP2B6 activity in humans. Bupropion pharmacokinetics were studied after a single oral dose of 150 mg in 121 healthy male volunteers. The amino acid polymorphisms R22C, Q172H, S259R, K262R and R487C were analysed by polymerase chain reaction and restriction fragment length polymorphism and plasma concentrations were measured by high-performance liquid chromatography. Pharmacokinetic analysis was performed by non-parametric methods and by population pharmacokinetic modelling. A unimodal distribution of bupropion and hydroxybupropion kinetic parameters was detected with a mean (range) area under the curve (AUC) of 3.64 (0.89-8.14) micromol.h/l for bupropion and 25.5 (6.72-75.3) micromol.h/l for hydroxybupropion. Population kinetic analysis revealed that bupropion total clearance via CYP2B6 alleles *1, *2, *5 and *6 did not differ, but clearance via allele *4 was 1.66-fold higher compared to wild-type allele *1 (P=0.001). Corresponding to the high clearance of bupropion, carriers of the CYP2B6 genotype *1/*4 had significantly higher Cmax of hydroxybupropion compared to all other genotypes (P=0.03). Only a minor fraction of the variability in bupropion and hydroxybupropion kinetics could be explained by the known CYP2B6 amino acid variants, in particular by the CYP2B6*4 allele. The role of this allele should also be studied in other CYP2B6 substrates, including cyclophosphamide, halothane, mianserin, promethazine and propofol.

Adult↗

Genetic polymorphisms in monoamine neurotransmitter systems show only weak association with acute post-surgical pain in humans.

BACKGROUND: Candidate gene studies on the basis of biological hypotheses have been a practical approach to identify relevant genetic variation in complex traits. Based on previous reports and the roles in pain pathways, we have examined the effects of variations of loci in the genes of monoamine neurotransmitter systems including metabolizing enzymes, receptors and transporters on acute clinical pain responses in humans. RESULTS: Variations in the catecholamine metabolizing enzyme genes (MAOA and COMT) showed significant associations with the maximum post-operative pain rating while the serotonin transporter gene (SLC6A4) showed association with the onset time of post-operative pain. Analgesic onset time after medication was significantly associated with the norepinephrine transporter gene (SLC6A2). However, the association between COMT genetic variation and pain sensitivity in our study differ from previous studies with small sample sizes, population stratification and pain phenotype derived from combining different types of pain stimuli. Correcting for multiple comparisons did not sustain these genetic associations between monoamine neurotransmitter systems and pain sensitivity even in this large and homogeneous sample. CONCLUSION: These results suggest that the previously reported associations between genetic polymorphisms in the monoamine neurotransmitter systems and the interindividual variability in pain responses cannot be replicated in a clinically relevant pain phenotype.

Acute Disease↗

[Effect of CYP2C19 genetic polymorphism on treatment efficacy of Helicobacter pylori infection with rabeprazole-based triple therapy in Chinese].

OBJECTIVE: To investigate the effect of different S-mephenytoin 4'-hydroxylase (CYP2C19) genotype on the eradication rate of Helicobacter pylori (Hp) by different rabeprazole-based triple therapy in Chinese. METHODS: 128 subjects with Hp positive gastritis or peptic ulcers were randomly assigned to receive 10 mg rabeprazole twice daily with 1000 mg amoxicillin twice daily and 500 mg clarithromycin (RAC group) or 400 mg metronidazole (RAM group) twice daily for 1 week. The CYP2C19 genotype (homozygous extensive metabolizer, hom-Ems; heterozygous extensive metabolizer, het-Ems; or poor metabolizer, PMs) was determined by the polymerase chain reaction-restriction fragment length polymorphism method. More than 4 weeks after completion of treatment, Hp status was assessed by (13)C-urea breath test. RESULTS: The hom-Ems, het-Ems and PMs were 30.5%, 50.0% and 19.5% in 128 subjects, respectively. The eradication rates in the rabeprazole-amoxicillin-clarithromycin (RAC) for clarithromycin-sensitive strains and rabeprazole-amoxicillin-metronidazole (RAM) for metronidazole-sensitive strains groups were 98.1% and 91.3%, respectively, on a per protocol basis. It decreased significantly eradication rates of Hp because the prevalence of primary antimicrobial resistance was 66.8% for metronidazole. When the statistical significance of each parameter associated with treatment outcome was assessed with logistic regression analysis, CYP2C19 genetic polymorphism did not show significant effect on the efficacy of anti-Hp therapy with rabeprazole-based triple regimens. CONCLUSIONS: The efficacy of rabeprazole-based triple regimens is less affected by the CYP2C19 genotype, the RAC regimen can be considered in Chinese.

2-Pyridinylmethylsulfinylbenzimidazoles↗

Sociobiology and HLA genetic polymorphism in hill tribes, the Irula of the Nilgiri hills and the Malayali of the Shevroy hills, south India.

Two endogamous tribes of Tamil Nadu, South India, the Irula of the Nilgiri hills and the Malayali of the Shevroy hills, were studied for their sociobiology and HLA polymorphism. For sociobiological studies 166 marriages in the Irula and 368 marriages in the Malayali were recorded. The number and spatial distribution of patrilineal clans and their marriageable range (number of clans from which the brides came) were studied. Eight clans in the Irula and 16 clans in the Malayali were identified. Of these the Kuppar of the Irula and the Malayan of Malayali were the largest clans, and both of them had the greatest marriageable range. The numerical strength and the resultant spatial distribution correlated well with the marriageable range. HLA-A, B, and DR polymorphism was studied on 191 Irula and 42 Malayali following standard procedures. HLA typing revealed high frequencies (> 10%) of alleles HLA-A2, A9, A11, B17, B35, B40, DR2, and DR7 in both tribes, but the Irula had elevated HLA-A10, B8, and DR8 frequencies and the Malayali had elevated HLA-A31, B7, DR4, and DR5 frequencies. Two-locus haplotypes A10-B8 and A2-B5 were identified in both tribes, but A11-B40 and A2-B53 were present only in the Irula and A33-B44 and B15-DR6 were present only in the Malayali. The sociobiology of the Irula was correlated to the HLA genetic profile. The Irula sample was stratified based on clan and HLA data; The Kuppar clan was closer to the Kalkatti, the second largest clan, than to the Pungar and the Sambar clans. Thus the numerical strength and spatial distribution of various exogamous clans, presumably a result of migration during different periods of history, is reflected in the marriageable range and thus in the genetic distance. In studying HLA or any other genetic polymorphism of an endogamous tribe or caste, one needs to consider the social structure, spatial distribution, and marriageable range.

Emigration and Immigration↗

[Genetic polymorphism of 6 short tandem repeat loci in Mongolian population of China].

OBJECTIVE: To clarify the distribution of genetic polymorphism of D3S1358, D13S317, D5S818, D6S1043, D2S1772, D7S3048 loci of the Mongolian population in Ximeng pastoral area and construct the relevant genetic database. METHODS: Multiplex PCR and polyacrylamide gel electrophoresis were used to investigate the polymorphism of 6 short tandem repeat (STR) loci in 286 individuals of the Mongolian population. RESULTS: In this study, 6, 9, 8, 11, 14, 11 alleles were observed at the 6 STR loci respectively. The genotypes distributions in Mongolian population were in accordance with Hardy-Weinberg equilibrium (P>0.05), the cumulative expected heterozygosities (H), discriminating probability (DP) and the polymorphism information contents (PIC) for the 6 loci were 0.9998, 09999, 0.9998 respectively. These data were compared with those of the Han population. The results showed there were significant difference in D3S1358, D13S317, D5S818, D2S1772, D7S3048 loci between the Mongolian population and Han population (P<0.05). However, no significant difference in D6S1043 locus was seen between the two populations (P>0.05). CONCLUSION: The results demonstrate that these 6 STR loci can serve as genetic marks and provide valuable data which are beneficial to studying the population genetics and ethnology.

China↗

Genetic polymorphism of serum vitamin D-binding protein (GC) in sheep and mouflon.

One-dimensional polyacrylamide gel electrophoresis (1D PAGE) followed by immunoblotting revealed genetic polymorphism of GC protein in sheep (variants F, S, V) and mouflon (variants F and S, apparently identical to F and S of sheep). The frequency of Gcs allele ranged from 0.84 to 1.0 in the 12 breeds of sheep studied. GcV allele was observed only in Tsigai breed with a frequency of 0.017.

Alleles↗

Relationship between genetic polymorphisms of alcohol and aldehyde dehydrogenases and esophageal squamous cell carcinoma risk in males.

AIM: To investigate the association between the genetic polymorphisms of ADH2 and ALDH2, lifetime alcohol consumption and esophageal cancer risk in the Taiwanese men. METHODS: Between August 2000 and June 2003, 134 pathologically-proven esophageal squamous cell carcinoma male patients and 237 male controls were recruited from Kaohsiung Medical University Hospital and Kaohsiung Veterans General Hospital in southern Taiwan. ADH2 and ALDH2 polymorphisms were genotyped using PCR-RFLP. RESULTS: Compared to those with ADH2*2/*2, individuals with ADH2*1/*2 and ADH2*1/*1 had 2.28- and 7.14-fold, respectively, increased risk of developing esophageal cancer (95%CI = 1.11-4.68 and 2.76-18.46) after adjusting for alcohol consumption and other covariates. The significant increased risk was also noted among subjects with ALDH2*1/*2 (adjusted OR (AOR) = 5.25, 95%CI = 2.47-11.19), when compared to those with ALDH2*1/*1. The increased risk of esophageal cancer was made greater, when subjects carried both ADH2*1/*1 and ALDH2*1/*2, compared to those with ADH2*1/*2 or ADH2*2/*2 and ALDH2*1/*1 (AOR = 36.79, 95%CI = 9.36-144.65). Furthermore, we found a multiplicative effect of lifetime alcoholic consumption and genotypes (ADH2 and ALDH2) on esophageal cancer risk. CONCLUSION: Our findings suggest that polymorphisms of ADH2 and ALDH2 can modify the influence of alcoholic consumption on esophageal cancer risk.

Aged↗

Xenobiotic metabolism, genetic polymorphisms and male infertility.

Male reproductive function may be impaired by various occupational and environmental chemical agents. The majority of these xenobiotics, however, require metabolic activation in order to exert adverse effects via covalent interactions between intermediate metabolites and cellular macromolecules such as DNA or protein. In addition, metabolization may alter endocrine-disrupting properties of xenobiotics. Thus tissue-specific expression and regulation of multiple xenobiotic-metabolizing enzymes are likely to play an important role in chemically induced disorders of male reproductive organs. Recent studies suggest that genetic polymorphisms underlying inter-individual and inter-ethnic variability of xenobiotic metabolism modulate susceptibility to male reproductive disorders. For cytochrome P450 1A1 (CYP1A1), a key enzyme in extra-hepatic metabolic activation of lipophilic xenobiotics, increased frequencies of two genetically linked polymorphisms have been found among infertile men.

Enzymes↗

CYP3A5 and MDR1 genetic polymorphisms and cyclosporine pharmacokinetics after renal transplantation.

BACKGROUND: The immunosuppressive drug cyclosporine (INN, ciclosporin), whose pharmacokinetic characteristics vary greatly among individuals, is a substrate for cytochrome P450 (CYP) 3A and P-glycoprotein, the product of the multidrug resistance 1 (MDR1) gene. Some of the single nucleotide polymorphisms (SNPs) in these genes are associated with deficient protein expression and reduced in vivo activity. We postulated that, in renal transplant recipients, these SNPs could be associated with interindividual variations in cyclosporine pharmacokinetics. PURPOSE: In 106 renal transplant patients, we evaluated retrospectively the effects of 4 MDR1 SNPs [T-129C, C1236T, G2677(T,A), and C3435T] and of the CYP3A5*1/*3 SNP on cyclosporine pharmacokinetic parameters and exposure indices. RESULTS: The CYP3A5*1 allele was present in 8.5% of patients. The MDR1 C1236T, G2677(T,A), and C3435T SNPs were frequent (17.9%, 18.9%, and 33%, respectively, for the variant homozygous genotype) and exhibited incomplete linkage disequilibrium. None of the cyclosporine pharmacokinetic parameters were associated with the CYP3A5 genetic polymorphism. Patients with the wild-type genotype in MDR1 C1236T SNP had slightly but significantly lower dose-adjusted peak drug concentrations (-16%) (P <.02) and dose-adjusted area under the concentration-time curve (AUC) values over the first 4 hours (-14%) (P <.05) as compared with mutated allele carriers. Haplotype analysis including MDR1 C1236T, G2677(T,A), and C3435T SNPs showed no significant association between haplotypes and cyclosporine pharmacokinetics or systemic exposure, although there was a nonsignificant trend toward higher dose-adjusted AUC values over the first 4 hours and AUC over the 12-hour administration interval for the T-T-T haplotype. CONCLUSION: The presence of the CYP3A5 SNP does not explain the high variability of cyclosporine pharmacokinetics in stable renal transplant patients. Despite the weak association found for the MDR1 C1236T SNP, MDR1 SNPs are unlikely to be useful for cyclosporine dose optimization in clinical practice.

ATP Binding Cassette Transporter, Subfamily B, Mem↗