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PubMed2026

EST-SSR based genetic polymorphism among Lablab (Lablab purpureus L. Sweet) accessions contrasting for drought stress at seedling stage.

Lablab is a multipurpose and the most drought-tolerant (DT) crop compared with its relatives. Despite its potential, Lablab is still an underutilized crop with a lack of improved varieties in many countries. The DT (D349, D147, HA4, D363, D352, D359, D348, D311, D55 and D250) and drought-susceptible (DS) (D271, D66, D106, D6, D26, D255, D28, D186, D95, and D258) accessions were earlier identified according to their morphological and biochemical responses to moisture stress at the seedling stage. These accessions were used to establish genetic polymorphism among the accessions contrasting for drought stress based on the Expressed Sequence Tag-Simple Sequence Repeats (EST-SSR) markers. The CTAB protocol was employed for the genomic DNA extraction. After DNA quality and quantity verification, the PCR was conducted using 16 EST-SSR primer pairs specific to the Lablab. The products were separated through the horizontal polyacrylamide gel electrophoresis (hPAGE). Discriminating ability of the markers and primers' efficiency were evaluated based on various genetic parameters. Principal Coordinate Analysis (PCoA) was performed to estimate the distance matrix among the population and among the accessions. While cluster analysis was processed to trace the genetic relationship among the accessions, dendrogram was constructed to decipher their genetic relationship. Analysis of Molecular Variance (AMOVA) was finally computed to quantify the diversity level and genetic relationship among the population, and among the accessions. A low polymorphism (GD = 0.19) was observed between the DT and DS accessions, likely due to limited discriminatory power of the EST-SSR markers. However, the PCoA, cluster analysis and AMOVA identified DT (D147, HA4, and D349) and DS (D106, D95, and D271) accessions as strongly contrasting populations under drought stress, with D147, HA4, D349, D363, D359, D352, and D348 further recommended as DT accessions. Given the low polymorphism observed, further validation using more informative molecular markers and advanced genomic approaches is recommended to improve the identification of drought-tolerance genes and related QTLs to support Lablab breeding programs.

Expressed Sequence Tags↗
PubMed2006

[Recent advances in the studies of genetic polymorphisms in diabetic retinopathy].

Diabetic retinopathy is one of the most serious complications of diabetes mellitus, which affects the health and life quality seriously. The development of procedures for prevention and treatment of diabetic retinopathy is one of the most important problems that should be solved. Epidemiological studies indicate that the development of diabetic retinopathy is not only determined by duration of diabetes and blood glucose control; individual diversities also play an important role. Some patients have a long course of disease and poor control of blood glucose, but they do not have diabetic retinopathy or only show slight pathological changes after a long term follow-up. Other patients only have a short term disease and well control of blood glucose, but they develop serious proliferative diabetic retinopathy. These patients usually have a positive family history. This phenomenon may relate to various genetic liabilities. This review introduce the recent advances in the studies of genetic polymorphisms in diabetic retinopathy.

Diabetic Retinopathy↗
PubMed2002

[Genetic polymorphism of FIBRA,DHFRP2 and ACTBP2 and their forensic application in Yunnan Han population].

To investigate the genetic polymorphism of FIBRA,DHFRP2 and ACTBP2 in Yunnan Han population as well as their application in forensic science, EDTA-blood specimens were collected from 200 healthy individuals. The DNA were extracted either by the Chloro form, phenol method or by the Chelex-100 method. The PCR products were analyzed by PAG vertical electrophoresis,following by silver staining. All gene frequencies, discrimination power (DP), exclusion of paternity probability (EPP), heterozygosity (H),polymorphisms information content (PIC),matching probability (PM) as well as the Hardy-Weinberg test were calculated. The obtained data are beneficial in the understanding of population genetics of the three STR loci in Yunnan Han population and the results suggest that these loci are valuable genetic markers for paternity testing and personal identification in forensic science practice.

English Abstract↗
PubMed1997

Genetic polymorphism of drug metabolising enzymes in African populations: implications for the use of neuroleptics and antidepressants.

Metabolism of most drugs influences their pharmacological and toxicological effects. Drugs particularly affected are those with a narrow therapeutic window and that are subjected to considerable first-pass metabolism. Much of the interindividual and interethnic differences in effects of drugs is now attributable to genetic differences in their metabolism. Genetic polymorphisms have been described for many drug-metabolising enzymes in Caucasian and Oriental populations, the most well-characterised being those for cytochrome P450 2D6, cytochrome P450 2C19, glutathione S-transferases, and N-acetyl transferase 2. African populations have been studied to a lesser extent, but it is apparent that populations within Africa are heterogeneous with respect to these polymorphisms. In addition, although some allelic variants are common to all populations throughout the world (e.g., CYP2D6*5), some allelic variants are specific for an African population (e.g., CYP2D6*17). The polymorphisms give rise to enzymes with changed or no activity towards drug substrates. Two of the most important enzymes for metabolism of neuroleptics and other psychoactive drugs are CYP2D6 and CYP2C19. This article compares the current information on polymorphisms of these two enzymes in African and other populations and discusses the implications of these polymorphisms for neuropharmacotherapy.

Africa↗
PubMed2001

Genetic polymorphisms of cytochrome P450 2A6 in a case-control study on lung cancer in a French population.

Cytochrome P450 2A6 (CYP2A6) is involved in the C-oxidation of nicotine and in the metabolic activation of tobacco nitrosamines. Recent data have suggested that CYP2A6 genetic polymorphisms might play a role in tobacco dependence and consumption as well as in lung cancer risk. However, the previously published studies were based on a genotyping method that overestimated the frequencies of deficient alleles, leading to misclassification for the CYP2A6 genotype. In this study, we genotyped DNA from 244 lung cancer patients and from 250 control subjects for CYP2A6 (wild-type allele CYP2A6*1, and two deficient alleles: CYP2A6*2, and CYP2A6*4, the latter corresponding to a deletion of the gene) using a more specific procedure. In this Caucasian population, we found neither a relation between genetically impaired nicotine metabolism and cigarette consumption, nor any modification of lung cancer risk related to the presence of defective CYP2A6 alleles (odds ratio = 1.1, 95% confidence interval = 0.7-1.9).

Aryl Hydrocarbon Hydroxylases↗
PubMed2005

beta2-adrenergic receptor activation and genetic polymorphisms in autism: data from dizygotic twins.

Gestational and genetic factors can contribute to autism during infancy and early childhood through their effects on fetal brain development. Previous twin studies have shown strong genetic components for the development of autism, a disorder that can have multiple causes. We investigated the effects of prenatal overstimulation of the beta2-adrenergic receptor in dizygotic twins who were exposed to terbutaline, a selective beta2-adrenergic receptor agonist used to treat premature labor, as a gestational factor. As a possible genetic mechanism, we studied two beta2-adrenergic receptor polymorphisms in twins from whom DNA was available: glycine substitution at codon 16 (16G) and glutamic acid substitution at codon 27 (27E), which show diminished desensitization in vivo compared with the wild-type receptor. Continuous terbutaline exposure for 2 weeks or longer was associated with increased concordance for autism spectrum disorders in dizygotic twins (relative risk = 2.0), with a further increase in the risk for male twins with no other affected siblings (relative risk = 4.4). A significant association was found between the presence of 16G and 27E polymorphisms in autistic patients compared with population controls (P = .006). Prenatal overstimulation of the beta2-adrenergic receptor by terbutaline or by increased signaling of genetic polymorphisms of the beta2-adrenergic receptor that have diminished desensitization can affect cellular responses and developmental programs in the fetal brain, leading to autism.

Autistic Disorder↗
PubMed1995

[Genetic polymorphism and gene geography of the indigenous population of the Ural region. I. Genetic structure of the peoples of the Ural region].

The genetic patterns of 25 populations from seven ethnic groups living in the Ural region (Komi, Komi-Permyaks, Udmurts, Mansi, Nentsy, Tatars, and Chuvashes) were studied. Immunological, biochemical, and physiological markers of the loci ABO, FUT, RH, P, FY, DI, KEL, LU, LE, JK, HP, GC, C'3, TF, PI, ACP1, GLO1, ESD, PGD, PGM1, PTC, and CB were studied. The average ethnic frequencies of the alleles and haplotypes studied were estimated. It was demonstrated that the Ural populations living to the west of the Urals, although of different origin, were more similar genetically than populations of common (Ural) origin living on different sides of the Urals, with respect to the majority of the traits studied.

Alleles↗
PubMed1990

Rapid and efficient detection of genetic polymorphism in wheat through amplification by polymerase chain reaction.

The polymerase chain reaction (PCR) was used to amplify genomic DNA of several wheat genotypes. The oligonucleotides used as primers were the terminal sequences of a gamma-gliadin gene. The electrophoretic analysis of the PCR products showed specific bands which revealed both inter- and intra-specific genetic polymorphism among the examined genotypes. The technique is proposed as a very simple and efficient alternative to RFLP markers.

Base Sequence↗
PubMed1992

Genetic polymorphism in sheep plasma detected using antibodies to human plasminogen.

Protein variation was identified in sheep when Western blots of polyacrylamide gels (routinely used to resolve transferrin polymorphism) were stained using antibodies to human plasminogen. The affinity of the antibodies to ovine plasma was less than 7% that of a human standard but they bound specifically to a single polymorphic protein. In 146 lambs and their parents the inheritance of the ovine plasminogen antigen polymorphism was consistent with four autosomal alleles segregating codominantly. However, an additional two lambs had types which were incompatible with their putative parents. The pedigrees of these lambs were tested by DNA fingerprinting and shown to have been incorrectly recorded. The genetic polymorphism detected by human plasminogen antiserum provided a probability of sire exclusion (PE) ranging from 0.04 to 0.32 and a polymorphic information content (PIC) of 0.08 to 0.50 in flocks of five sheep breeds: Perendale, Romney, Merino, Texel and Coopworth (in order of increasing genetic variation in this locus). Significant differences in allele frequency were observed between breeds but sampling did not assess the variation among flocks within a breed.

Animals↗
PubMed2001

Typhoid fever and genetic polymorphisms at the natural resistance-associated macrophage protein 1.

Control of Salmonella enterica serovar Typhimurium (S. typhimurium) infection in the mouse model of typhoid fever is critically dependent on the natural resistance-associated macrophage protein 1 (Nramp1). In this study, we examined the role of genetic polymorphisms in the human homologue, NRAMP1, in resistance to typhoid fever in southern Vietnam. Patients with blood-culture-confirmed typhoid fever and healthy control subjects were genotyped for 6 polymorphic markers within and near NRAMP1 on chromosome 2q35. Four single base-pair polymorphisms (274 C/T, 469+14 G/C, 1465-85 G/A, and D543N), a (GT)(n) repeat in the promoter region of NRAMP1 and D2S1471, and a microsatellite marker approximately 130-kb downstream of NRAMP1 were examined. The allelic and genotypic frequencies for each polymorphism were compared in case patients and control subjects. No allelic association was identified between the NRAMP1 alleles and typhoid fever susceptibility. In addition, neither homozygotes nor heterozygotes for any NRAMP1 variants were at increased risk of typhoid fever.

Alleles↗
PubMed2006

[Genetic polymorphisms and infections].

Recent studies have shown that genetic variants, responsible for the different human response when facing an infectious risk, concerned the genes of proteins involved in either recognition of the infectious agent, in the inflammatory cascade, or in the coagulation process. For example, some studies clearly demonstrated that if a twin was affected by an infectious disease, the risk of infection by the same agent for the other twin was significantly higher in homozygote than in heterozygote twins. In Caucasians, a punctual mutation of the TLR2 cytosol was proved to block the response to bacterial lipoproteins and to some Gram positive bacteria and could be responsible for a greater susceptibility to septic shock. Several polymorphisms of the tlr4 gene have been involved in the onset of septic shock in postsurgery infection due to Gram(-) bacilli. Paradoxically, these variants seemed to protect against legionellosis. In pediatrics, polymorphisms of tlr4 were also clearly identified as risk factors for meningococcemia of severe bronchiolitis due to the respiratory syncytial virus (RSV) in children under 2 years of age. A polymorphism of the TLR5 receptor gene, which creates a stop codon and which is responsible for a nonfunctionality of the receptor was associated with the onset of severe legionellosis. Analysing the functions of these genetic polymorphisms in the onset of sepsis will open the way to a lot of research on specific treatments focused on genetic abnormalities.

Genetic Predisposition to Disease↗
PubMed2006

Genetic polymorphism at GSTM1 and GSTT1 gene loci and susceptibility to oral cancer.

GSTs are phase II enzymes which are involved in the detoxification of active metabolites of many potential carcinogens from tobacco smoke and therefore may play an important role in modulating susceptibility to tobacco related cancers. This study evaluates the influence of genetic polymorphisms of GSTM1 and GSTT1 gene loci on susceptibility to oral cancer. The genotyping was based on multiplex PCR assay that identified the GSTM1 and GSTT1 null (-/-) genotypes but didn't distinguish homozygous wild type+/+ and heterozygous +/- individuals. Genomic DNA was isolated from cases with oral cancer (n=40) and normal controls (n=87). The prevalence of the GSTM1 null genotypes was 29/87 (33.3%) and 21/40 (52.5%) in controls and oral cancer cases, respectively but the differences were not significant (OR=2.2; 95%CI=0.96-5.1; p=0.06). The frequency of homozygous GSTT1 null genotype in cancer cases was 17/40 (42.5%) as compared to 13/87 (14.94%) in controls and the differences were highly significant (OR=4.2; 95%CI=1.64-10.9; p=0.0002). Oral cancer cases had higher proportion of both GSTM1 and GSTT1 null genotypes as compared to controls but the differences were not statistically significant (OR=2.9; 95%CI=0.71-11.9; p=0.17). When individuals were categorized into two groups, no differences were observed for GSTM1 null genotype frequencies in control and cancer cases (OR=2.9; 95%CI=0.9-9.6; p=0.08) (OR=1.6; 95%CI=0.44-6.1; p=0.58) in <=50 yrs and >50 yrs of age groups. Significant differences between control and cancer cases were observed for GSTT1 null genotypes both in <=50 yrs and >50 yrs of age groups (OR=4.0; 95%CI=1.1-15.0; p=0.03) (OR=4.5; 95%CI=0.97-22.29; p=0.05), respectively. The effect of smoking on GSTM1 null individuals was not found significant (OR=1.0; 95%CI=0.19-4.86; p=0.75) but it was significant in case of GSTT1 null individuals (OR=6.33; 95%CI=1.0-44.1; p=0.02). Our results thus suggest that GSTT1 gene polymorphisms modulate susceptibility to tobacco-related cancer of the oral cavity.

Adolescent↗
PubMed1999

[C677T genetic polymorphism of methylenetetrahydrofolate reductase in premature coronary heart disease].

OBJECTIVE: Methylenetetrahydrofolate reductase (MTHFR) is an important factor responsible for hyperhomocysteinemia. The relation of MTHFR gene C677T polymorphism and premature coronary heart disease was studied. METHODS: MTHFR C677T genetic polymorphisms in 67 patients with premature coronary heart disease were detected by PCR-RFLP technique. RESULTS: In case group, the frequency of T homogenic type was 34.3% (23/67), heterogenic type 43.3% (29/67) and C homogenic type 22.4% (15/67). T allele frequency was 55.9% (75/134) while C allele frequency 44.1% (59/134) in case group. There were significant differences in MTHFR genotype and allele frequencies between cases and controls (chi 2 = 6.82 and 5.41 respectively, P < 0.05). CONCLUSIONS: It was suggested that MTHFR gene C677T mutation was a possible risk factor of Chinese premature coronary heart disease.

Adult↗
PubMed2001

[Meningococcal purpura fulminans: untoward result of genetic polymorphism?].

Despite significant progress in intensive care medicine, the mortality of septic shock has not changed in recent years. Early recognition of subtle signs in favor of meningococcal sepsis, early antibiotic treatment, and aggressive hemodynamic support remains the cornerstone of therapy of severe meningococcal shock in children. Recent work has emphasized the role of genetic polymorphisms in various systems to explain the most severe cases: anti-inflammatory cytokine profile IL-10/TNF-alpha, elevated levels of plasminogen activator inhibitor type-1, variants of the gene for mannose-binding lectin complement pathway. This may explain the disillusionment of pediatric intensivists, and the general failure of immunotherapy for sepsis. Reasonable hope lies upon new meningococcal vaccines.

Child↗
PubMed2003

Genetic polymorphisms in MDR1 and CYP3A4 genes in Asians and the influence of MDR1 haplotypes on cyclosporin disposition in heart transplant recipients.

Intestinal cytochrome P450 3A4 (CYP3A4) and P-glycoprotein (P-gp) both play a vital role in the metabolism of oral cyclosporine (CsA). We investigated the genetic polymorphisms in CYP3A4(promoter region and exons 5, 7 and 9) and MDR1 (exons 12, 21 and 26) genes and the impact of these polymorphisms on the pharmacokinetics of oral CsA in stable heart transplant patients (n = 14). CYP3A4 polymorphisms were rare in the Asian population and transplant patients. Haplotype analysis revealed 12 haplotypes in the Chinese, eight in the Malays and 10 in the Indians. T-T-T was the most common haplotype in all ethnic groups. The frequency of the homozygous mutant genotype at all three loci (TT-TT-TT) was highest in the Indians (31%) compared to 19% and 15% in the Chinese and Malays, respectively. In heart transplant patients, CsA exposure (AUC(0-4 h), AUC(0-12 h) and C(max)) was high in patients with the T-T-T haplotypes compared to those with C-G-C haplotypes. These findings suggest that haplotypes rather than genotypes influence CsA disposition in transplant patients.

Administration, Oral↗
PubMed2006

Genetic polymorphism of xenobiotic metabolising enzymes, diet and cancer susceptibility.

There is increasing evidence identifying the crucial role of numerous dietary components in modifying the process of carcinogenesis. The varied effects exerted by nutrient and non-nutrient dietary compounds on human health and cancer risk are one of the new challenges for nutritional sciences. In the present paper, an attempt is made to review the most recent epidemiological data on interactions between dietary factors and metabolic gene variants in terms of cancer risk. The majority of case-control studies indicate the significant relationship between cancer risk and polymorphic xenobiotic metabolising enzymes in relation to dietary components. The risk of colorectal cancer is associated not only with CYP2E1 high-activity alleles, but also GSTA1 low-activity alleles, among consumers of red or processed meat. Genetic polymorphisms of NAT1 and NAT2 may be also a breast-cancer susceptibility factor among postmenopausal women with a high intake of well-done meat. On the other hand, phytochemicals, especially isothiocyanates, have a protective effect against colorectal and lung cancers in individuals lacking GST genes. Moreover, polymorphism of GSTM1 seems to be involved in the dietary regulation of DNA damage. The European Prospective Investigation into Cancer and Nutrition study shows a significant inverse association between the polycyclic aromatic hydrocarbon-DNA adduct level and dietary antioxidants only among GSTM1-null individuals. However, the absence of a modulatory effect of polymorphic xenobiotic metabolising enzymes and diet on the development of cancer has been indicated by some epidemiological investigations. Studies of interactions between nutrients and genes may have great potential for exploring mechanisms, identifying susceptible populations/individuals and making practical use of study results to develop preventive strategies beneficial to human health.

Acyltransferases↗
PubMed1991

Genetic studies of human apolipoproteins. XX. Genetic polymorphism of apolipoprotein J and its impact on quantitative lipid traits in normolipidemic subjects.

Apolipoprotein J (apo J) is a newly identified member of a growing family of proteins associated with various lipoprotein particles. Apo J is a glycoprotein which exists in the plasma associated with high-density lipoprotein subfractions which also contain apo A-I and cholesteryl ester transfer protein (CETP). We have investigated the possible existence of genetic polymorphism at the apo J structural locus and have evaluated its role in lipid metabolism. By employing isoelectric focusing and immunoblotting techniques, we have screened plasma or serum samples from six population groups: U.S. whites, Amerindians, Eskimos, New Guineans, U.S. blacks, and Nigerian blacks. Apo J revealed a common two-allele polymorphism only in populations with African ancestry and was found to be monomorphic in all other population groups tested. The genetic basis of the two alleles designated--APO J*1 and APO J*2, at a single structural locus, apo J-- was confirmed in a large number of segregating families. In the U.S. blacks, the frequencies of the APO J*1 and APO J*2 alleles were .76 and .24, respectively, and in the Nigerian blacks these values were .72 and .28, respectively. In addition, a single example of a rare allele designated APO J*3 was also encountered in the U.S. black sample. In Nigerian blacks, the apo J polymorphism's impact on seven quantitative lipid traits--total cholesterol, LDL-cholesterol, HDL-cholesterol, HDL3-cholesterol, HDL2-cholesterol, VLDL-cholesterol, and triglycerides--was investigated. No significant impact of the apo J polymorphism was observed for any of these lipid traits.

Adolescent↗
PubMed2004

Genetic polymorphism within the leishmania donovani complex: correlation with geographic origin.

Random amplified polymorphic DNA (RAPD) was used to detect intraspecific diversity for the Leishmania donovani complex. Fifty-two decameric to 21-meric primers of arbitrary sequence were applied to 15 strains that belong to nine zymodemes. Strains belonging to the species L. major and L. tropica were used as outgroups. A total of 902 amplicons generated by RAPD were scored. Most primers produced species-specific profiles, only 0.6% amplicons were shared by all species, while 4.3% amplicons were common for all 15 strains of the L. donovani complex. Well-supported trees have been constructed, which show a rather strong correlation between the genetic polymorphism of studied strains and their geographic origin. In all obtained trees, L. infantum was paraphyletic. The RAPD profiles suggest that MON-30 belongs to L. donovani. Moreover, the genetic distance between the L. archibaldi strain and other leishmanias does not warrant existence of a separate species.

Africa↗